Top Russian officials met with survivors and relatives of victims of the Beslan school hostage seizure on Saturday, the third anniversary of the horrifying siege's beginning.

Townspeople held a memorial gathering in the wreckage of the school's gymnasium, where the hostages were held. They lay red flowers on the gymnasium's floor around a towering wooden cross erected in the gym's center; photos of the victims lined the walls.

Terrorists demanding independence for the Russian republic of Chechnya stormed into the southern Russian school on Sept. 1, 2004, the first day of the school year, seizing more than 1,000 hostages. including children, parents and teachers.

It ended two days later in a maelstrom of explosions and gunshots that left 334 people dead, more than half of them children. What triggered the violent end is still hotly debated and other questions continue to swirl over the tragedy, including how the heavily armed terrorists were able to travel to Beslan despite orders to police to keep security high on the opening day of school.

Dmitry Kozak, the presidential envoy for southern Russia, met with members of the Mothers of Beslan, the most prominent group that has been pushing for a full accounting of the siege, Russian news agencies reported.

"As long as terrorist attacks happen, the government and society bear responsibility for this," Kozak said in response to Mothers of Beslan leader Susanna Dudiyeva's criticism that the government is trying to deflect responsibility, the Interfax news agency reported.

Parliament Speaker Boris Gryzlov, who leads the pro-Kremlin party that dominates parliament, said that investigation of the tragedy is continuing.

"Questioning is under way and essential information is being collected. New circumstances have turned up in the course of the investigation and the investigative team certainly responds to them," Gryzlov said, according to Interfax.

President Vladimir Putin took note of the anniversary while visiting a school in Astrakhan to mark the opening of the school year.

"Despite the fact that today is a shining and very festive day, we cannot forget about the tragedy that happened a few years ago; we cannot forget those children who can never again go to school," he said in remarks shown on Russian television.

A final official report on the events has not been released. The lead parliamentary investigator has suggested homemade bombs rigged by the 32 heavily armed men and women in the gymnasium were detonated by them, and that was the primary reason for the high death toll.

But last month, the Beslan mothers' group released previously unseen video footage that appeared to cast doubt on that conclusion.

The footage shows homemade explosive devices — bottles filled with shrapnel and ball bearings that had been hung from basketball hoops and the roof of the gymnasium.

Men, who are not shown, can be heard talking. They appear to be bomb experts and the Kommersant newspaper said they were army engineers being questioned by prosecutors.

"The holes inside (on the walls) could not have been caused by these explosives," one of the men says. "All of these (ball bearings) would have been scattered around but on the children we brought out there was no evidence of these sorts of injuries."

Only one of the attackers is known to have survived. The man, Nur-Pashi Kulayev, was sentenced to life in prison in 2006.