A theatre audience in Moscow is being held hostage by up to 50 armed men and women who burst in during a performance Wednesday.

About 500 people are inside.

The attackers are Chechen rebels, and are demanding Russia end its war against Muslims in the state who are trying to separate.

Marquee of hostage theatre

They are threatening to blow up the theatre if Russian forces storm the building, according to patrons and backstage crew members who fled during the confusion early in the attack.

But late Wednesday, two Russian politicians entered the building to negotiate with the rebels.

Police and security forces are all around the building, but the start of talks suggests the Russians aren't planning an attack.

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Some children and Muslims were allowed to leave the theatre after the attackers took over, rushing into the building and shooting in the air.

People who fled the building said the attackers may have mined the theatre, and some wore explosives on their bodies.

The women may be widows of Chechen men killed by the Russians in the bloody war that has gone on for nearly a decade.

The musical being performed is called "Nord-Ost," one of the Russian capital's most popular productions.