A spate of anonymous bomb threats has continued in Russia despite the arrest of several suspects.
More than 50 schools were evacuated in the north of St Petersburg on Tuesday, state news agency TASS reported.
Threats were also made against schools in Rostov-on-Don in the south of the country, as well as against courts in Moscow.
Nothing suspicious was found at any of the sites in question.
The Federal Bureau for Security (FSB), Russia's domestic intelligence service, announced last Thursday that it had arrested 14 suspects in connection to the recent threats. Those detained have all been suspected of making bomb threats in the past.
Incidents of this sort have been a frequent occurrence in Russia for years. Besides schools, courts and shopping centres, threats have also been made of bombs on planes.
