A reporter close to the theatre said he had heard four to five gunshots near the building. It was not immediately clear who fired the shots or whether they came from inside the building, where some 700 people were being held hostage.

According to a freed hostage, the gunmen are demanding "an end to the war," indicating a link to the Chechen conflict. According to hostages who managed to contact police by telephone, they have begun placing bombs in the building. A reporter in the theatre said the gunmen allowed members of the audience to make phone calls and released children. Muslim members of the audience were also allowed to leave.

Reports say 20 to 30 gunmen seized the theatre, known as the former House of Culture in Melnikov Street in southeast Moscow. Neighboring buildings were being evacuated. President Vladimir Putin was informed of the incident, which happened on the eve of his official visit to Europe.