Putin said that the changes were crucial in the wake of last month’s hostage crisis in which gunmen seized School No. 1 in Beslan, North Ossetia, and held hostage about 1,200 children, teachers and parents. More than 300 hostages died and 100 people are still missing.

He later issued a decree giving the government two weeks to draft proposals to deal with emergencies and a month to prepare “appropriate measures on foreseeing and preventing terrorism in any form.” It called for proposals to improve the work of the security forces, whose performance in Beslan has been widely criticized, and to toughen controls on issuing visas and entering Russia.

But some analysts said the changes, which amount to the biggest single shakeup of Putin’s four years in power, would not help to fight terrorism, but would further strengthen his already tight grip on power. “The last link in the system of checks and balances, which has prevented an excessive concentration of power in one pair of hands, is being abolished,” the opposition party Yabloko said in a statement, Reuters reported.

Putin said that he wanted to appoint the currently elected regional governors himself, subject to vetting by the weak regional assemblies, and he wanted all M.P.’s elected by proportional representation, adding that this new system would help to improve the people’s control over the authorities in the fight against terrorism.

At present, half the Duma, the lower house of the federal parliament, is directly elected by constituencies, the rest according to the party vote. In theory, the new system could give smaller parties seats in the parliament, but the rules let only parties with more than 7 percent of the vote take seats, disqualifying most.

Putin made two other announcements of more apparent relevance to the Beslan disaster. He made his head of administration, Dmitri Kozak, his personal envoy to the North Caucasus region, which includes North Ossetia and Chechnya, in a move aimed at showing the president’s greater personal involvement in the region. He also appointed Vladimir Yakovlev as minister for reconstructed nationalities, a post designed to ease ethnic tension in the South that he abolished when be became president.

Putin hinted at plans for a Russian version of the U.S. Homeland Security Department, established after Sept. 11, saying: “We need a single organization capable of not only dealing with terror attacks but also working to avert them, destroy criminals in their hideouts and, if necessary, abroad.”

In a rare mention of the social causes of terrorism, he hinted at the huge amount of unemployment and poor health of the North Caucasus. He said that terrorism’s roots lay in “unemployment, in insufficiently effective socioeconomic policy and in insufficient education  The district’s unemployment rate is several times higher than Russia’s average  All of this provides fertile soil for extremism to grow.”

Lilia Shevtsova, a senior associate at the Carnegie Endowment for International Peace in Washington, said that the changes were the “logical extension” of Putin’s desire to have “vertical” control of the regions. “The constitution still says that the Russian people are the source of power, but [now] there is nothing left in the constitution to that effect,” she said. The changes would not make Putin a dictator, however, since he still values his invitations to the Group of Eight industrialized countries and the Russian authorities are too corrupt to be authoritarian, she added.

Vladimir Pribyovsky, head of the think tank Panorama, said: “Terrorism is being used as a pretext to change the federal structure of the country.” He said that the planned changes to the constitution might lead to Putin trying to alter it to allow himself a third term at the elections in 2008.

Before he won another term in March, Putin ruled out changes to the constitution.

The promise and expectation of the first day of term evaporated in the North Ossetian town of Beslan in southern Russia. Seventeen gunmen, some wrapped in explosives, swept into Middle School 1, running into the school courtyard from the nearby railway station and sparking Russia’s most serious domestic crisis since the Dubrovka theatre siege two years ago.

Diana fled. She hid in the boiler room with 14 others, a teacher and a parent who had been attending the ceremony.

“We managed to peek through the crack in the door,” she said. “The gunmen were armed with machine guns and my teacher noticed one girl among them wearing a mask. Someone said they were speaking in Chechen.”

Amid the disinfectant of newly scrubbed floors and the gleam of whitewashed walls, the attackers filed through the school corridors.

Moments later, Diana heard an Ossetian voice outside the room. “We whispered to him, ‘help us get out’. He did, yet as we ran from the boiler room, the [militants] noticed us. Some of us were grabbed by them and were taken off to the sports hall. Now I am here, outside, and they are there.”

Inside, scores ofpupils aged from seven to 17 were herded into the school’s sports hall along with parents and teachers. One official estimate put the total number held at 336. According to reports, mines were laid about them, and children posted at the windows to prevent sniper fire.

The suicide bombers eventually made their demands clear in incipient negotiations with the authorities: the release of 24 prisoners, fellow militants captured in a recent raid, talks with the presidents of North Ossetia and neighbouring Ingushetia and Russian withdrawal from Chechnya  a demand that no Russian president can meet.

The Kremlin called an emergency sitting of the UN security council in a bid to shore up international support for its inevitable backlash. President George Bush was one of the first to express condolences and solidarity in a message the Kremlin portrayed as support for Russia’s own peculiar war on terror.

Earlier in the day, President Vladimir Putin pledged that he would never negotiate with terrorists or even Chechen separatists. But with the bloody end of the Dubrovka theatre siege  in which 129 people were fatally gassed during a Russian assault  still fresh in the popular consciousness, the Kremlin strongman needs to minimise casualties.

Outside the school the reason for a soft approach was clear. Relatives milled around, dumbstruck that a decade of conflict in the nearby republic of Chechnya had crossed the border to wreak such havoc with their families. Two corpses lay near the school building. A sniper on the roof kept doctors away from one girl, who lay wounded in the inner grounds of the building.

Mothers screamed at helpless policemen. One was shown on television saying: “How long can this madness in the country continue? When will it end?”Another wailed: “Exchange us for the children. What are our children guilty of?” Another said: “This was my child’s first day at school. He was so happy and told me: ‘Mum, I will be a good student’. Please, take me, take me, instead.”

The local authorities struggled to retain control of the situation as the day progressed. A brief shootout between police and the hostage takers ended with reportedly seven people dead, including two officers, and a dozen wounded. The gunmen fired rocket-propelled grenades at an armoured personnel carrier that approached the building.

A videotape was given to police by the militants, according to Oleg Tsagolov, a spokesman for the president of North Os- setia. It was blank. The mobile phone number they gave did not work. The militants refused to accept food for their hostages.

A man answered the school phone, according to the New York Times, and said he was part of a group led by Shamil Basayev, the Chechen field commander who has led several chilling, deadly raids into Russia over the past decade.

The gunmen said they would execute 50 hostages for each one of them that was killed, and 20 for each wounded.

The gunmen had entered North Ossetia from neighbouring Ingushetia, Mr Tsagolov said. “They captured a police captain in Koli-Gou, and then came in his car [and a military truck] to Beslan.”

He said the policeman escaped and told officials there were 17 militants, many wearing suicide bomber belts, including two women.

One schoolboy, Arsene Dedeyev, 15, told the Russian NTV television channel that a friend had seen the militants “standing far away from school a while ago, looking at it with binoculars”.

Anatoli Sikoyev, a parent in his fifties, described from Beslan hospital his lucky escape. “When I heard the news I rushed to school to save my family. I approached the schoolyard and came across a man with a huge beard. He shouted at me: ‘lie down and crawl backwards’  Then another man shot at me from a window, hitting my hand and skimming my head.”

One policeman, carrying his AK – 47, whose son was inside the school, said: ” The life of a child is priceless, and for their lives I will do everything I can. But if Moscow orders an assault, I will kill the person who gives the order.”