A series of anonymous bomb threats phoned in to authorities in cities across Russia have prompted evacuations at schools, shopping malls, theaters, and universities.
Local reports said the evacuations took place mainly in Siberia and the Far East since the evening of September 10.
Some regional media quoted local police as saying that the evacuations were linked to drills, but other reports quoted officials who said they were the result of anonymous bomb threats.
A spokeswoman of the Chelyabinsk regional police, Olga Shterk, said on September 12 that the Federal Security Service was involved in the investigation into what she called a "spam attack."
"The phone calls were made via the Internet and therefore it will be difficult to locate the site from where the calls were made,” Shterk said. “There are programs allowing to make phone calls from tablets, smartphones, and so on. The caller might have hidden his/her whereabouts using special software.”
Reports said security officials evacuated tens of thousands of people from dozens of buildings in Novy Urengoi, Omsk, Perm, Krasnoyarsk, Magadan, Yuzhno-Sakhalinsk, Vladivostok, Ufa, Chelyabinsk, Kopeisk, Yekaterinburg, Kaliningrad, and other cities.
Searches in the evacuated buildings have revealed no bombs or explosives in any of the cities.
The first evacuation reportedly took place at the mayor's office in Omsk after an unknown person called the authorities saying there was a bomb in the building.
In Perm, authorities canceled classes at schools across the city after anonymous callers phoned in bomb threats at the mayor's office, seven schools, and a train station.
The governor of Stavropol Krai, Vladimir Vladimirov, said that similar bomb threats triggered the evacuation of buildings in the regional capital, Stavropol, and suggested that the phone calls might have come from abroad.
Reports from the Siberian city of Surgut said armed men in military uniforms had been stopping vehicles to carry out searches.
There was no official announcement by security officials about the vehicle checks.