Russian security forces are on high alert after an armed gang of Chechen guerrillas invaded a Moscow theatre taking hundreds of people hostage. Special anti-terrorist troops have said they will not try to storm the building unless the gunmen begin killing hostages. It follows a threat earlier by the rebels to detonate explosives strapped to their bodies if police tried to enter. They said they would kill ten hostages for every gunman injured. Around 40 masked men and women carrying guns, grenades and explosives burst into the auditorium during a musical last night firing shots in the air and shouting "Stop the war in Chechnya".