On October 23, 2002, a group of about 40 armed men and women took control of the Dubrovka theatre in the south east of Moscow during a performance of a musical, and they held about 850 people in the hall. The group said it was acting for Chechen fighters and demanded the withdrawal of Russian forces from Chechnya and an end to the war there, and it set a deadline and threatened to shoot the hostages. Some of the group wore explosive belts. The siege began.
The standoff lasted almost three days. Some people were released during it, including children and foreign citizens, and the hostage takers allowed doctors and journalists in, and the Russian authorities negotiated while preparing an assault. Offers to exchange prisoners were refused. The siege was long. On the morning of October 26 the special forces pumped an aerosol anaesthetic into the ventilation of the hall and then entered, and most of the hostage takers were shot.
The gas caused the deaths of many of the hostages. The rescue was deadly. They were carried out unconscious and laid on the pavement outside, and the emergency services were not told what the gas was, which made treatment difficult, and 129 hostages died, almost all of them from the effects of the gas and from being laid in positions that stopped them breathing. Questions about the substance used were never fully answered. It is reported to have been a fentanyl based agent.
The attack led to changes in Russian policy on security and to a harder line in the war in Chechnya, and it was followed by other attacks, including the school siege at Beslan in 2004. The handling of the crisis was criticised inside and outside Russia, and a parliamentary inquiry and later a European court decision examined the actions of the authorities. The theatre was reopened some years later.