Russian news agencies are reporting that security officials have arrested two men who were allegedly armed with explosives.
The two men were reportedly found in southwestern Moscow with belts packed with what appeared to be explosives.
According to the Interfax news service, both the men were Chechens, but there was no official confirmation of this.
Officials from the Federal Security Service and a bomb squad went to the scene and an investigation is under way.
In October, a group of Chechen gunmen demanding an end to the war in the breakaway region of Chechnya took hundreds of people hostage in a Moscow theater. Many of the hostage-takers wore explosives strapped to their bodies and threatened to blow up the building.
Since then, Russian security forces have reported finding similar explosive material in the city, as they have stepped up security and searches.