The broken bodies of hundreds of children were pulled from the rubble of this bereaved town's School No. 1 on Saturday, pushing the death toll well above 300 in an attack that President Vladimir Putin denounced as an "inhuman, unprecedentedly cruel" terrorist crime.

Angry relatives searched in vain to identify their loved ones at morgues. But a day after a 52-hour hostage standoff at the school in southern Russia culminated in a bloody battle, they found corpses burned beyond recognition by an explosion that had crumpled the roof over the school gym.

"We've been trying to give them hope," said Emma Kusova, after she added one more name to the list of at least 260 missing Saturday night. "But none of these people are alive."

Putin said the attack on the school, which began Wednesday morning as students and their parents arrived for the first day of classes, constituted "direct intervention of international terrorism against Russia." He harshly criticized the security services and promised a forceful response. "We showed weakness, and the weak are trampled upon," Putin said.

Officials reported more than 340 dead and about 700 wounded by late Saturday. But authorities acknowledged there had been close to 1,200 hostages, and the death toll could still rise substantially. A large percentage of the victims were children.

Russian officials described the school seizure in the North Ossetia region as a carefully planned operation in which the attackers had secretly planted weapons and explosives inside the building in advance. "The rebels prepared beforehand," said Valery Andreyev, head of the regional Federal Security Service.

But few details emerged about the guerrillas, described by officials as a mix of ethnic Chechens, Ingush, Russians and Arabs, and there were conflicting reports about whether any of the attackers survived and escaped.

Putin, wearing a somber black suit and tie, spoke in a videotaped address to the nation from the Kremlin 13 hours after making a surprise pre-dawn visit to Beslan. He blasted Russia's security services for corruption and for allowing the country's borders to go unprotected. But he did not mention Chechnya, or talk about the years-long war in the separatist republic that has given rise to a campaign of terror around the country.

Instead, Putin blamed international terrorists for the wave of attacks that has killed hundreds of civilians over the last year. Government officials said that 10 of the 26 guerrillas killed in Beslan were Arabs. Meanwhile, a Muslim group declaring loyalty to al Qaeda leader Ayman Zawahiri took credit for the school seizure in a Web statement.

"We are dealing with direct intervention of international terrorism against Russia," Putin said, "with a total, cruel and full-scale war in which our compatriots die again and again."

In Beslan, recriminations were directed not only at the heavily armed insurgents who stormed into the school demanding an end to the war in nearby Chechnya, but also at the president who rose to power based on his vow to harshly prosecute that war.

"What happened is the fault of the president, only his," said Bibo Dzudtsev as he stood outside the House of Culture where families held a vigil during the crisis. Like many in the crowd searching for missing loved ones and for answers, Dzudtsev said he believed Putin's government lied throughout the school seizure. "Everyone is deceiving us. They're telling us there were Arabs. There were no Arabs. They were lying about the number of hostages. And now they're lying about the number of dead."

Up until Friday's battle, authorities had said there were 350 hostages in the school, though many in Beslan had already concluded that the real number was closer to 1,200. Now that the worst had happened, the anguished people of this town expressed anger once more, because the official death toll was far lower than the estimated 500 most believed had perished.

Regional leader Alexander Dzasokhov appeared to suggest that townspeople were right to complain they had not been told the truth. "Now it is our duty to tell the people here the truth, to show what really happened," Dzasokhov, the president of North Ossetia, told Putin during his early-morning visit to Beslan.

But Dzasokhov and other local officials were shouted down when they tried to reassure residents.

"We'll do everything we can," the regional finance minister told the crowd at the House of Culture. But he was drowned out by shouts of "We haven't found our relatives," "How could the terrorists get through all the checkpoints?" "Is the president going to resign?"

Another politician also sought to calm the crowd. "Let's just concentrate on burying the dead," he said.

Most of the dead were trapped beneath the wreckage of the school gym, whose roof collapsed at about 1 p.m. Friday when the guerrillas detonated explosives they had rigged around the room. Workers cleared the rubble, using a bulldozer to scoop up the debris. Refrigerated trucks took the bodies away.

At the main morgue in the nearby city of Vladikavkaz, about 150 unclaimed corpses were stacked in corridors and some were even outside in the parking lot late Saturday. Many had been so badly burned that they were charred beyond recognition. Many were the bodies of small children.

Relatives wandered in the rows of bodies, some of which were in black body bags, others wrapped in foil or plastic. Those walking there wore masks or pulled shirts above their noses to block the smell of death. People who found their loved ones put them in caskets and took them away; others kept searching. The sound of wailing periodically erupted in the otherwise silent ranks.

Zarina and Zhanna Basayeva waited outside while their brothers searched for their missing 9-year-old niece. They'd already found a dead cousin and had been back and forth between the hospital and the morgue several times. "Our brothers go in, look around and don't find her, and we get all hopeful," said Zarina. They wiped their eyes and headed off again, but did not look very hopeful.

There were a few happy reunions on an otherwise grim day. One group of children was found alive Saturday morning hiding in the basement of the school where they had fled at the start of the fighting, Lev Dzugaev, spokesman for the regional president, said in an interview.

But many of Beslan's 30,000 residents were searching.

Aza Pukhayeva rushed around the city with snapshots of her 12-year-old niece, Madina. Pukhayeva approached two boys at the House of Culture, showing them a picture of Madina in a bright yellow T-shirt. The boys said they had seen her in the school, but only before the bomb exploded.

Pukhayeva cried for a moment. "We've been to all the hospitals, but she's not on any list. She's not on the list of the dead either," Pukhayeva said. "She's probably still there." And then Pukhayeva jumped into her beat-up Lada Sputnik car and raced off.

Pages of names posted at Beslan's hospital suggested there were still survivors to be found. Each of the 543 entries documented one of the injured, along with a description. Among those injured were children shot from behind when they fled as the guerrillas started firing, witnesses said.

Many of the injured were listed simply as "unknown," such as No. 32 on one of the lists: "Unknown, approximately 14 years old. Diagnosis: Multiple shrapnel wounds to the body and head. Burns. Shock."

Authorities gave conflicting accounts of what had happened to the guerrillas during and after a battle that raged from 1 p.m. Friday until 2 a.m. Saturday. Estimates ranged from 26 hostage takers to as many as 40, and officials refused to publicly confirm who was in the group. Russian media have quoted sources saying the hostage takers were allied with Chechen rebel leader Shamil Basayev and led by Ingush fighter Magomed Yevloyev, code name "Magas."

Deputy Prosecutor-General Sergei Fridinsky said 26 guerrillas had been killed and none remained at large. "We think that not a single person managed to escape," he told reporters.

However, groups of special forces troops patrolled Beslan searching for possible escapees and Putin ordered the borders to North Ossetia closed while the hunt continued. In one residential neighborhood, a squad of soldiers knocked on doors and stopped passersby. They forced one woman to take off her sweater, saying they wanted to examine her shoulders.

Asked why, they said they were searching for a female terrorist, who was reported to have been wounded and would have a bruise from a rifle butt.

Glasser reported from Moscow.

Putin criticized security services.Paramedics at a morgue in Vladikavkaz register the bodies of those who were killed in the chaotic ending of the school seizure in Beslan. Outside a hospital in Beslan, people searching for news of their relatives read lists of hostages who escaped from the school during the fighting that ended the school siege.Emergency workers collect bodies outside the wreckage of the school taken over by separatists in the southern town of Beslan.Russian President Putin visits an injured victim of the school siege during a pre-dawn visit to a hospital in Beslan. Putin harshly criticized Russia's security services.