Russian authorities say a rash of anonymous bomb threats that have prompted mass evacuations is continuing.
Officials said that more than 1,500 people were evacuated from at least five schools in the capital, the Moscow Oblast legislature, and other buildings after about 30 anonymous bomb threats were received in about one hour on October 6.
Tens of thousands of people have been evacuated from schools, malls, theaters, universities, hotels, and government buildings in cities nationwide amid a wave of anonymous bomb threats that began on September 10.
Bombs have not been discovered in any of the cases, and weeks of silence from among law enforcement authorities on possible suspects or motives prompted wide-ranging speculation.
Federal Security Service (FSB) Director Aleksandr Bortnikov said on October 5 that four Russian citizens suspected of organizing the wave of anonymous bomb threats had been identified.
Bortnikov said that the four suspects were living abroad and had accomplices inside Russia.
He did not name the suspects or say anything about a possible motive of what President Vladimir Putin's spokesman has called "telephone terrorism."
With reporting by TASS, Interfax, and RIA Novosti