The officials said 20 of the 23 killed on Monday were on Sanaa’s central Hayel street. They included a child and at least three soldiers who defected to join the protesters. Mortar shells thought to have been fired by pro-regime forces killed another two people in the capital, said the officials, who spoke on condition of anonymity because they were not authorized to share the information.

Tens of thousands of protesters demonstrated in Sanaa Sunday to press demands for Saleh to step down. Pro-regime snipers killed at least 26 of the protesters.

Beside those killed, scores of protesters suffering gunshot wounds were taken to hospitals in Sanaa, according to Mohammed al-Maqtari, a doctor at a field hospital set up by the protesters. The wounded included soldiers from the 1st Armored Division, which, along with its commander, joined the protesters more than six months ago.

Witnesses said the soldiers were involved in skirmishes with the Presidential Guards.

In the southern city of Taiz, at least one protester was killed and 15 others were wounded Monday in clashes between anti-regime demonstrators and security forces, according to witnesses. In the southern port city of Aden, three protesters were wounded in clashes with government forces, witnesses there said.

Yemen’s protest movement has stepped up demonstrations in the past week, angered after Saleh deputized Vice President Abed Rabbo Mansour Hadi last week to negotiate further on a Gulf-mediated, U.S.-backed deal under which he would step down in return for immunity from prosecution. Saleh has already backed away three times from signing the deal.

Many believe the move is the latest of many delaying tactics. Saleh has resisted calls to resign.

The United States once saw Saleh as a key ally in the battle against the dangerous Yemen-based al-Qaida branch, which has taken over parts of southern Yemen under cover of the political turmoil in the country. The U.S. withdrew its support of Saleh as the protests gained strength.

All of this is occurring against a backdrop of civil unrest and fighting in Yemen, where the regime of President Ali Abdullah Saleh has been trying to violently suppress opposition protesters for months. For an update on the situation in Yemen and the U.S. military campaign there, I spoke to Gregory Johnsen, a respected Yemen analyst and a Ph.D. candidate in Near Eastern studies at Princeton.

There’s a Wall Street Journal piece this week saying unnamed U.S. officials are worried about al-Qaida in the Arabian Peninsula staging attacks outside of Yemen. What’s your read on how much of a threat this group is?

With regards to the Wall Street Journal story, I’m not sure how much of that is new. Al-Qaida in the Arabian Peninsula has for quite some time been really explicit in talking about targeting both Western and Yemeni government interests within the country as well as going after regional targets — as well as of course going after the United States, as was shown on Christmas Day 2009 and in the parcel bomb plot last year.

The situation right now is very murky. There has been a great deal of fighting in the southern province, Abyan, which has been going on throughout most of the summer. There’s a group that calls itself Ansar al-Shariah, or the supports of Shariah (Islamic law), that have been fighting with the Yemeni military in the capital of the province. There have also been a number of U.S. airstrikes targeting these militants. The belief is that Ansar al-Shariah is affiliated with or linked to al-Qaida, but most of that comes from a single interview, so we don’t have a lot of information to back it up. Al-Qaida itself has not put out a great deal of publication materials since the protests in Yemen really got started. So at the moment we have a lot more questions than we have answers.

Do we know how many people there actually are in this al-Qaida in the Arabian Peninsula group?

A couple years ago, the foreign minister of Yemen came forward with the idea that there were 300 individuals in the group. Since he said that, many in the media have picked up on that and run with it, but I think it was really just his best guess. This year, for example, the Yemeni government has announced it has killed 200 or 250 members of al-Qaida since the fighting began earlier this spring. And we see on the ground that there are still people fighting for the organization and carrying out attacks in Abyan. So we don’t have a very good sense of the numbers.

My reading of the situation is that al-Qaida in the Arabian Peninsula has actually gotten stronger in recent years, largely because of U.S. airstrikes. The U.S. has managed to kill some key mid-level commanders, but many of these individuals have been replaced quite quickly. And as the U.S. has killed them, there has been a significant amount of what’s often referred to as collateral damage. That is, innocent women and children or unaffiliated civilians who are killed in these airstrikes. That tends to not only fit into al-Qaida’s argument that Yemen is a legitimate theater of jihad, but also the people that have died tend to have brothers and uncles and cousins. We’re seeing more and more people becoming radicalized.

Who exactly is being killed by all this American bombing? Is it clear to anyone what’s really happening?

It’s not at the moment. The problem is that the town of Zanjubar, where a lot of the fighting is going on now, has many internally displaced people. We’ve seen some video coming out of the city but it’s really hard to confirm. There aren’t a lot of journalists working on the ground. And the Yemeni government has of course sort of eroded away in the face of the protests in the last couple months, so it’s hard for international journalists to work on the ground. Most of what has come out is either official statements by the Yemeni government or very sketchy unverified reports that are being passed through several intermediaries.

How intense is the American military campaign?

We know that the U.S. is certainly carrying out air and drone strikes. We know that the U.S. tried to kill Anwar al-Awlaki, the Yemeni-American cleric, on May 5, and they missed. We know another individual who is on the FBI’s Most Wanted list was targeted about a week ago, and they missed him as well. We’re not always sure who is doing the bombing. There have been a number of instances where the Yemeni government falsely claimed to have carried out an air raid on a particular militant hideout. For instance there was a case where the militants had taken over a police station in a particular town, and the government claimed it had carried out an air raid on the station. It later turned out that it had actually been U.S. missiles that were fired. So it’s become very difficult for outsiders to piece together what’s going on because there is a lot of misinformation.

Earlier this month, President Saleh appeared on TV in a badly burned state from Saudi Arabia, a few weeks after a bombing at his palace. With all the protests and fighting, what’s the state of the regime right now?

Essentially the military has switched. Large portions of it have defected and have joined what’s broadly being called the protest movement. The other half of it — the Republican Guard and other parts that are commanded by Saleh’s relatives — remain loyal to their commanders. This is the standoff. The government doesn’t have a great deal of control over large portions of the country. It’s only really in some urban areas where the Saleh government continues to carry out attacks against protesters.

Taking a step back, what we have is a very large anti-Saleh coalition made up of different interest groups within Yemen. Many of them have been opposed to one another but are currently being held together in an alliance against President Saleh. It’s a very fragile, creaky alliance. There’s a lot of bad blood and mistrust among the various actors. It’s a very tense political stalemate while the president is out of the country. Everyone is sort of waiting around to see what happens next.

What role is the Obama administration playing besides the bombing?

The criticism that a lot of people have is that the U.S. is only looking for someone who is willing to partner with them to attack al-Qaida. Officially the U.S. has come out and said it’s time for President Saleh to step down and it would like to see a very orderly political transition. But this has been difficult. There was a Gulf Cooperation Council proposal that was put forward three times during the spring. President Saleh each time said he would sign it; each time he balked at the last minute and did not sign. I think it’s become clear that Saleh isn’t going to step down unless he’s really forced out. What we’re seeing is that the U.S., as well as Saudi Arabia, either doesn’t have or isn’t using the proper amount of leverage with which to force President Saleh out. So now we have a situation where the country is crumbling: There are very severe problems with water shortages, with electricity, with gas shortages. The U.S. can fire as many missiles as it wants to against militants, but the situation in Yemen and the situation combating al-Qaida is not going to get any better until there’s some kind of political transition. But we haven’t seen the kind of creative diplomacy that would require — either from the U.S. or from Yemen’s neighbors.

Wednesday’s escape was the latest sign that Yemen’s months-long upheaval has emboldened al-Qaida militants to challenge authorities in the country’s nearly lawless south.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP’s earlier story is below.

SANAA, Yemen (AP) — The head of Yemen’s most powerful tribal confederation warned Tuesday in a letter to the Saudi king that Yemen could plunge into civil war if President Ali Abdullah Saleh is allowed to return home.

Saleh is currently in Saudi Arabia, where he is receiving treatment for serious injuries from a blast early this month at his palace in the Yemeni capital that left him with severe burns and chunks of wood in his chest.

In his message to King Abdullah, Sadeq al-Ahmar, the influential tribal chief who was an ally of Saleh before switching sides to join the opposition, appealed to the Saudi monarch to prevent Saleh from returning to Yemen.

“His return will lead to sedition and civil war,” al-Ahmar said, according to an aid to al-Ahmar. Saudi Arabia is a key player in Yemen, and has pressed Saleh in the past to negotiate a settlement to Yemen’s political turmoil.

Late Tuesday, al-Ahmar had his first meeting with Vice President Abed Rabbo Mansour Hadi since Saleh departed, a possible step toward resolving the conflict. Maj. Gen. Ali Mohsen al-Ahmar, a general who defected to the opposition and deployed his units to defend protesters, took part in the meeting. Hadi is the acting president. He is under pressure to agree to a new government that effectively freeze Saleh out.

The tribal chief’s aide said that they discussed steps to implement a cease-fire and withdraw forces from the streets. They also discussed “possible means to exit the current crisis,” according to the aide, who spoke on condition of anonymity because he was not authorized to speak to reporters.

Hundreds of thousands of Yemenis, inspired by uprisings elsewhere in the Mideast, have been protesting daily since late January, demanding the ouster of Saleh, who has ruled Yemen for nearly 33 years. Their campaign has been largely peaceful, but fighting erupted in Sanaa between Saleh loyalists and fighters from al-Ahmar’s powerful tribal confederation, the Hashid, after troops moved to attack al-Ahmar’s residence.

The fighting has tapered off since Saleh left for Saudi Arabia. Vice President Abed Rabbo Mansour Hadi became acting president following Saleh’s departure.

The opposition on Tuesday accused Saleh’s inner circle and family of hindering the opposition’s dialogue with Hadi.

“Saleh’s sons are not helpful in solving the problem, and they don’t help the acting president to exercise his constitutional powers,” opposition spokesman Abdullah Oubal said.

Yemen’s opposition parties have sought to persuade Hadi and Saleh’s ruling party to join them in a transitional leadership that would effectively shut out Saleh, who has resisted tremendous pressure at home and abroad to step down.

The president’s son Ahmed, who commands the country’s best trained military forces, the Republican Guard, and is the main force maintaining his father’s grip on power, opposes such discussions.

Saleh’s close aide and adviser, Abdul-Karim al-Iryani, arrived Tuesday in Riyadh for talks with Saleh, who requested the meeting. A leading member of the ruling party, commenting on reports that Saleh and al-Iryani were discussing a transfer of power, said he expected “very important decisions” to come out from the meeting.

He spoke on condition of anonymity because of the sensitivity of the issue.

The United States fears that Yemen’s power vacuum will give even freer rein to al-Qaida’s branch in Yemen, which Washington believes is the terror network’s most active branch. Already, Islamic militants — some suspected of ties to al-Qaida — have taken control of at least two areas in the rebellious southern province of Abyan.

Late Monday and early Tuesday, government warplanes bombed suspected militant hideouts in Abyan, killing at least 22 al-Qaida-linked fighters, a defense ministry official said on condition of anonymity in line with ministry regulations.

“His return will lead to sedition and civil war,” al-Ahmar said, according to a statement from his office. Saudi Arabia is a key player in Yemen, and has pressed Saleh in the past to negotiate a settlement to Yemen’s political turmoil.

Hundreds of thousands of Yemenis, inspired by uprisings elsewhere in the Mideast, have been protesting daily since late January demanding the ouster of Saleh, who has ruled Yemen for nearly 33 years. Their campaign has been largely peaceful, but fighting erupted in Sanaa between Saleh loyalists and fighters from al-Ahmar’s powerful tribal confederation, the Hashid, after troops moved to attack al-Ahmar’s residence.

The fighting has tapered off since Saleh left for Saudi Arabia, and vice president, Abed Rabbo Mansour Hadi, became acting president following Saleh’s departure.

The opposition on Tuesday accused Saleh’s inner circle and family of hindering the opposition’s dialogue with Hadi.

“Saleh’s sons are not helpful in solving the problem and they don’t help the acting president to exercise his constitutional powers,” opposition spokesman Abdullah Oubal said.

Yemen’s opposition parties have sought to persuade Hadi and Saleh’s ruling party to join them in a transitional leadership that would effectively shut out Saleh, who has resisted tremendous pressure at home and abroad to step down.

The president’s son Ahmed, who commands the country’s best trained military forces, the Republican Guard, and is the main force maintaining his father’s grip on power, opposes such discussions.

Saleh’s close aide and adviser, Abdul-Karim al-Iryani, arrived Tuesday in Riyadh for talks with Saleh who requested the meeting. A leading member of the ruling party, commenting on reports that Saleh and al-Iryani were discussing a transfer of power, said he expected “very important decisions” to come out after the meeting.

He spoke on condition of anonymity because of the sensitivity of the issue.

The United States fears that Yemen’s power vacuum will give even freer rein to al-Qaida’s branch in Yemen, which Washington believes is the terror network’s most active franchise. Already, Islamic militants — some suspected of ties to al-Qaida — have taken control of at least two areas in the restive southern province of Abyan.

Late Monday and early Tuesday, government warplanes bombed suspected militant hideouts in Abyan, killing at least 22 al-Qaida-linked fighters, a defense ministry official said on condition of anonymity in line with ministry regulations.