On October 23, 2002, about 40 Chechen terrorists took hostage an audience of around 900 people at a Dubrovka theater performance of the musical Nord-Ost. The terrorists demanded the immediate withdrawal of Russian troops from Chechnya.
After three days of appeals and negotiations, Russian security forces used an undisclosed gas to disable terrorists before they could carry out their threat to blow up the hall.
The Russian authorities say 39 terrorists were killed in the raid, and 130 hostages died of the effects of the gas. There is some dispute amongst survivors of the siege as to the number of terrorists involved.
After a minute of silence observed at the official ceremony on Sunday, white balloons, one for each hostage who died, were released into the sky. Relatives of victims of other terrorist acts, both in Russia and abroad, had been invited to the ceremony.
