WATCH: Thousands of people were evacuated from shopping malls, railway stations, a university, and other buildings in Moscow on September 13 following some 20 threatening phone calls. (Reuters)
A series of anonymous bomb threats phoned in to authorities across Russia has continued with new threats in Moscow and St. Petersburg.
Moscow police sources say more than 9,000 people were evacuated from eight schools in the Russian capital on September 14 as a result of anonymous bomb threats.
Hundreds of people were also evacuated from several shopping malls in St. Petersburg on September 14 following anonymous threats by telephone.
Since September 10, similar calls have triggered mass evacuations at schools, malls, theaters, and universities in many cities and towns across Russia.
Bombs have not been discovered in any of the cases.
Kremlin spokesman Dmitry Peskov said on September 14 that the bomb threats amount to "telephone terrorism."
Peskov also said that "all necessary measures are being taken" to find the perpetrators.
RIA Novosti news agency quoted an unnamed security official as saying that investigators had traced the calls to people based abroad who were linked to the extremist group Islamic State and other organizations.
IS militants have claimed responsibility for a series of deadly attacks in Russia, including a suicide bombing in St. Petersburg in April that killed 14 people.
On September 12, Chelyabinsk regional police spokeswoman Olga Shterk called the wave of bomb threats 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.
The first hoax bomb threats to be reported was on September 10 at the mayor's office in Omsk when an unknown caller told authorities there was a bomb in the building.
On September 13, Moscow police sources say more than 100,000 people were evacuated from about 70 buildings after at least 65 anonymous bomb threats.
With reporting by TASS, Interfax, Bloomberg, and AP