MOSCOW, October 23 (RIA Novosti) - Six years after Chechen terrorists burst onto the stage during the Nord-Ost musical in Moscow's Dubrovka theater, the victims of the ensuing siege were honored in the Russian capital on Thursday.

The official ceremony to commemorate the deadly conclusion of the siege will be held on Sunday, but Thursday's anniversary was marked by people laying flowers at a monument to the victims of terrorism outside the theater building.

On October 23, 2002, about 40 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.

The ceremony on Sunday will see a minute of silence followed by a religious service outside the theater. White balloons, one for each hostage who died, will then be released into the sky. Relatives of victims of other terrorist acts, both in Russia and abroad, have been invited to the ceremony.

On the eve of the anniversary of the start of the siege, lawyers for one of the survivors and relatives of a journalist who perished during the rescue operation filed a case with a Moscow court to attempt to reclaim money they say was not returned to them after the conclusion of the events of late October 2002.