MOSCOW, October 11. /TASS/. Ten people are being checked on suspicion of involvement in the preparation of a terrorist attack in Moscow, a source in law enforcement agencies told TASS on Sunday.

"Law enforcers are working with ten people to establish the role of each of them in the preparations for a terrorist act," the source said.

Investigative actions in the apartment in a residential house in Strelbishchensky Pereulok street in central Moscow, where a group of suspects was detained, are over.

A spokesman for the National Anti-terrorist Committee told TASS earlier on Sunday, security officers had detained a group of persons suspected of involvement in the preparation of the terrorist attack in Moscow had been detained in an apartment house in central Moscow. An explosive device was found and rendered harmless in the apartment.

A police source said a possible yield of the explosive device could exceed four kilograms of TNT. According to the source, the operation was conducted in an apartment on the last, ninth, floor of the building. More than 120 residents were asked to leave the house. Gas supplies to the house were cut during the special operation.

Currently, police are patrolling the area.