A police official says a suicide bomber has killed 15 people in eastern Afghanistan, including a key tribal leader.
Police Gen. Mohammad Ayub Salangi says the bomber set off his explosives next to a small group of tribal elders and government workers as they were meeting Monday with a few hundred Afghan refugees who had recently returned from Pakistan.
He says 15 people were killed in the blast in Nangarhar province and at least 15 others wounded. Among the dead was Mohammad Zaman, an influential tribal leader in the area and a former mujahedeen fighter.
THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.
KABUL (AP) -- A NATO airstrike killed at least 27 civilians in central Afghanistan, the Cabinet said Monday, the third time a mistaken coalition strike has killed noncombatants since the start of a major offensive in the south aimed at winning over the population.
The top NATO commander, U.S. Gen. Stanley McChrystal, apologized to the Afghan president, NATO said.
The Afghanistan Council of Ministers strongly condemned the airstrike Sunday in Uruzgan province, calling it "unjustifiable."
It said reports indicated that NATO planes fired at a convoy of three vehicles, killing at least 27 people, including four women and a child, and injuring 12 others.
It urged NATO to "closely coordinate and exercise maximum care before conducting any military operation" to avoid further civilian casualties.
The airstrike was not related to the massive ongoing NATO offensive on the southern Taliban stronghold of Marjah in neighboring Helmand province. But it could still hurt government and NATO efforts to win support from the local population in their fight against Taliban militants.
NATO confirmed that its planes fired on what it believed was a group of insurgents on their way to attack NATO and Afghan forces, but later discovered that women and children were in the vehicles. A number of people were killed and the injured were transported to medical facilities, it said in a statement.
The Afghan government and NATO have launched an investigation.
Interior Ministry spokesman Zemeri Bashary said the airstrike hit three minibuses traveling on a major road near Uruzgan's border with central Day Kundi province. There were 42 people in the vehicles, all civilians, he said.
Bashary said local investigators had collected 21 bodies and two people were missing. He said he was checking with Cabinet officials to find out why there was a discrepancy in the toll.
The NATO statement did not say how many people died or whether all the occupants of the vehicles were civilians.
"We are extremely saddened by the tragic loss of innocent lives," Gen. McChrystal said in the statement. "I have made it clear to our forces that we are here to protect the Afghan people and inadvertently killing or injuring civilians undermines their trust and confidence in our mission. We will redouble our effort to regain that trust."
On Saturday, Afghan President Hamid Karzai admonished NATO troops for not doing enough to protect civilian lives. During a speech at the opening session of the Afghan parliament, Karzai called for extra caution from NATO.
"We need to reach the point where there are no civilian casualties," Karzai said. "Our effort and our criticism will continue until we reach that goal."
NATO has gone to great lengths in recent months to reduce civilian casualties -- primarily through reducing airstrikes and tightening rules of engagement -- as part of a new strategy to focus on protecting the Afghan people to win their loyalty over from the Taliban.
But mistakes have continued. In the ongoing offensive against Marjah, two NATO rockets killed 12 people in one home and others have been caught in the crossfire. At least 16 civilians have been killed so far during the offensive, NATO says, though human rights groups say the number is at least 19.
On Thursday, an airstrike in northern Kunduz province missed targeted insurgents and killed seven policemen.
It was public outrage in Afghanistan over civilian deaths that prompted McChrystal to tighten the rules last year.
A total of 2,412 Afghan civilians were killed last year, the highest number in any year of the eight-year war, according to a U.N. report. But deaths attributed to NATO troops dropped nearly 30 percent as a result of the new rules, it said.
The Marjah offensive is the largest joint NATO-Afghan operation since a U.S.-led invasion ousted the Taliban government from power in 2001. It's also the first major ground operation since President Barack Obama ordered 30,000 reinforcements to Afghanistan.
Gen. David Petraeus, who oversees the wars in Afghanistan and Iraq, said on NBC's "Meet The Press" that Marjah was the opening salvo in a campaign to turn back the Taliban that could last 12 to 18 months.
But the continued toll of civilian lives will make it harder for NATO in its goal to win over the support of local Afghans against Taliban militants in the south.
The newly appointed civilian chief for Marjah was to arrive Monday to begin the task of restoring government authority after years of Taliban rule even though NATO troops are still battling insurgents in the area.
District leader Abdul Zahir Aryan will be flying into Marjah for the first time since the NATO offensive began Feb. 13. He plans to meet with community leaders and townspeople about security, health care and reconstruction, he said in a phone interview Sunday.
"The Marines have told us that the situation is better. It's OK. It's good," Aryan said. "I'm not scared because it is my home. I have come to serve the people."
Ajmal Samadi, a spokesman for Afghan Rights Monitor in Kabul, said there is a shortage of medical care in Marjah and a scarcity of food means prices have skyrocketed.
One man told the group's representatives that he had spent the past few days looking for a sack of flour. Another family offered to sell a sack for about twice the normal price. "He said 'I can't afford it. I have other things we need to buy,'" Samadi said.
The International Committee of the Red Cross said Monday that it had evacuated 28 sick and injured civilians from Marjah to treatment facilities outside the area since the beginning of the offensive. Most required life-saving medical treatment, the ICRC said.
Meanwhile, in the east of the country, NATO forces said they killed 14 insurgents in two separate clashes -- one in Kapisa province and one in Kunar.
Khan reported from Kandahar, Afghanistan. Associated Press writers Heidi Vogt, Deb Riechmann and Tini Tran in Kabul contributed to this report.