Moscow theater hostage crisis

The Moscow theater hostage crisis, also known as the 2002 Nord-Ost siege, was the seizure of the crowded Dubrovka Theater in Moscow by Chechen terrorists on 23 October 2002, resulting in the taking of 912 hostages. The attackers, led by Movsar Barayev, claimed allegiance to the rebel breakaway movement in Chechnya. They demanded the withdrawal of Russian forces from Chechnya and an end to the Second Chechen War. The crisis ended when Russian security services released sleeping gas into the building, and subsequently stormed it, killing all 40 hostage takers. 132 hostages died, largely due to the effects of the gas. Due to the layout of the theater, special forces would have had to fight through 30 metres (100 ft) of corridor and advance up a well-defended staircase before they could reach the hall in which the hostages were held. The attackers had numerous explosives, with the most powerful in the center of the auditorium. Spetsnaz operators from Federal Security Service (FSB) Alpha and Vympel, supported by a Russian Ministry of Internal Affairs (MVD) SOBR unit, pumped a chemical agent into the building's ventilation system and began the rescue operation. The identity of the gas was not disclosed at the time, although it was believed to have been a fentanyl derivative. A study published in 2012 concluded that it had been a mixture of carfentanil and remifentanil. The same study pointed out that in a 2011 case at the European Court of Human Rights, the Russian government stated that the aerosol used was a mixture of a fentanyl derivative and a chemical compound with a narcotic action.