Alexander Tsekalo, a producer whose show was performed in the hall at that time, told Russia's First TV channel that about 1,000 people might be held in the hall. But earlier Itar-tass report cited law enforcement sources as saying that there were some 700 people in the hall.

Police units and an Alpha special forces unit went to the sceneand sealed off the area. Transportation was cut off in the area, where relatives of the held people were waiting in cold and wet weather.

Olevjina Bobova, an actress of the show, escaped from the third floor of the hall by climbing out of the window through a "rope" made with curtain.

She told Xinhua outside the hall that some 20 attackers, including men and women who speak in Georgian and Chechen accent, entered the concert hall at about 21:00 Moscow time (1800 GMT) and had fired intensively into the air.

She said the gunmen had released Georgian and children, but most of the more than 600 audience and the show staff were still being held hostage.

The attackers had grenades and explosive devices with them, shesaid.

The Interfax quoted a released child as saying that the demand of the attackers was to "end the war." There has no official confirmation on this so far.

The agency said one of its reporters was inside the concert hall at the time of the raid. She said by telephone that the gunmen prevented the audience from leaving the theater, but allowed them to make telephone calls.

Her latest call said the attacks had started letting children out of the hall and latest Interfax report said some 20 children had been freed. The agency also quoted sources at the Moscow police headquarters as saying that the gunmen also released all Muslim hostages.

The Interfax reporter said some of the gunmen were armed with assault rifles. She also claimed the gunmen were of Caucasian origin.

Russian presidential press secretary Alexei Gromov said President Vladimir Putin had been immediately informed of the attack.

The concert hall, located in southeastern Moscow, was staging aperformance of the musical Nord-Ost, one of the Russian capital's most popular productions.

(Xinhua News Agency October 24, 2002)