Wails from grief-stricken residents of this southern Russian town interrupted a moment of silence Saturday, a year to the day that hundreds died in a hail of gunfire and explosions at the horrific end to a school hostage crisis.

President Vladimir Putin (search) ordered his prosecutor-general to send investigators for a fresh investigation into Russia's worst terrorist attack, acknowledging searing criticism of the authorities' handling of the school seizure and the subsequent investigation. He ordered the inquiry a day after meeting with a delegation of Beslan residents.

By 1:05 p.m., the time of the first explosion that ended the three-day hostage crisis, at least 4,000 people had squeezed into the courtyard outside the Beslan (search) school gymnasium where the victims endured terror, thirst and hunger.

As a bell tolled, children released 331 white balloons into the air to symbolize the souls of the dead. The moment of silence was broken by a wave of wailing that rippled through the crowd, and at least one woman collapsed.

"They died here, they were burned here, their souls are still here," said Alona Bistayeva, 42, standing in the line of dazed-looking people waiting to file through the gymnasium. "It's a process of farewell, and of not forgetting. A person forgets this, and all of a sudden it happens again."

From the school, the crowd moved to the cemetery, where thousands watched the consecration of a soaring new memorial while weeping women tended their relatives' graves.

As bells tolled over loudspeakers, a short poem was read out and then the names of all 331 victims that took 25 minutes to get through. Some people wept; most bowed their heads.

The sobbing swelled as a white sheet was pulled off the 25-foot statue of four women holding up a tree of angels.

White doves released into the air circled over the crowd several times as mourners bent down and touched the earth on their relatives' graves with both hands.

In the Russian capital, fags flew at half-staff and a pro-Kremlin youth group held a large memorial ceremony off Red Square (search) to mark the Beslan anniversary. The state-run media called on opposition forces not to try to take advantage of the tragedy to sow discord.

Putin opened the weekly meeting of his Security Council with a moment of silence. He then announced that he had instructed prosecutors to send investigators to Beslan to verify the information he had been given at the meeting with members of a mothers' committee who have demanded that negligent or corrupt officials be prosecuted over the attack.

"They are disturbed by how the investigation is being conducted," and to date has not explained "the circumstances that allowed the terrorist attack to become possible at all," Putin said in televised comments.

"They (the prosecutors) will have to conduct exhaustive, additional verification of the entire sum of information about this case," Putin said.

Beslan Mothers' Committee leader Susanna Dudiyeva told reporters after Friday's meeting that the group still held Putin personally responsible for the tragedy and that Putin told them he feels guilty. The president reiterated that Saturday.

"You know, like every country in the world, Russia is a target of terrorist attacks and unfortunately our country, like many others, does not always turn out to be able to effectively repulse these attacks, work to prevent terrorist attacks," Putin said.

"Each of us, both as a citizen and as a function of his official position, bears responsibility for everything that happens in this sphere," he said.

According to the Kommersant daily, a delegation member told Putin he had been misinformed.

"What has been reported to you is not objective," the newspaper quoted Viktor Yesiyev, who had been held hostage in the school. "And we decided to tell you how it was in Beslan in those days in fact, from our own side."

Militants attacked School No. 1 on Sept. 1, 2004 — the first day of classes — taking more than 1,100 children, parents and staff hostage and herding them into the gymnasium, which they rigged with explosives. Most of the 331 victims — including 186 children — died in a firestorm of explosions and gunfire that brought the crisis to a bloody end nearly three days later.

The rebels, who were demanding that Russian troops withdraw from the nearby breakaway province of Chechnya, crossed heavily policed territory to reach the school and victims' relatives are convinced they received help from corrupt officials.