The man walked into the polling center and threatened to detonate an explosive device.
"Security forces have tackled the man who threatened to bomb a polling station," the police source said. The source added that the attacker held four people hostage on the first floor of the building. He wore a suspicious belt with a button.
Moscow’s City Election Commission said the bomb threat had not been confirmed. It said the attacker "pretended to have planted a bomb. There was, of course, no bomb, and the man has been detained."
Moscow Mayor Sergei Sobyanin thanked police forces for their professionalism. The incident occurred as Russians went to the polls to elect 450 lawmakers to the State Duma, the lower house of the national parliament.