The Moscow theater hostage crisis, also known as the 2002 Nord-Ost siege,,,,
Was the seizure of the crowded Dubrovka Theater on 23 October 2002 by 40 heavily armed Chechens wearing bomb belts who claimed allegiance to the Islamist militant separatist movement in Chechnya. They took 850 hostages and demanded the withdrawal of Russian forces from Chechnya and an end to the Second Chechen War. The siege was officially led by Movsar Barayev. After a three days siege, Russian Alpha Group forces pumped an unknown chemical agent into the building’s ventilation system and raided it.
During the raid, all 40 of the attackers were killed by Russian forces, and about 130 hostages died due to adverse reactions to the gas (including nine foreigners) and over 700 got injured. All but two of the hostages who died during the siege were killed by the toxic substance pumped into the theater to subdue the militants.The use of the gas was widely condemned as heavy-handed, but Moscow insisted it had little room for maneuver, as they were faced with the prospect of 50 heavily armed rebels prepared to kill themselves and their hostages.Physicians in Moscow condemned the refusal to disclose the identity of the gas that prevented them from saving more lives. However, some reports said the drug naloxone was successfully used to save some hostages.