Putin calls St. Petersburg blast a 'terror attack'

Russian president has called Wednesday's explosion in St. Petersburg a "terror attack," according to local media on Thursday.

"A terror attack was committed in St. Petersburg yesterday. The Federal Security Service [FSB] recently thwarted another attempted terror attack," said Russia's official news agency TASS, quoting Vladimir Putin.

At a meeting in Moscow with military personnel, the president instructed the director of the FSB to "act within the law ... while working with these terrorists, when detaining them," adding, however, "if there is a threat to the lives and health of our employees, our officers, to act decisively, not to capture anyone and eliminate gunmen on the spot," TASS said.

Thirteen people were injured when an explosion hit a supermarket in St. Petersburg on Wednesday evening.

According to Russian news agency RIA Novosti, over 50 people were evacuated from the store in the Baltic port city.