The Polish foreign ministry has said it is “shocked” after the Russian authorities reported that at least 10 people were killed in a blast at a metro station in St. Petersburg on Monday.

“We are shocked by the events in Petersburg. We convey our condolences and expressions of solidarity to those close to the victims,” the Polish foreign ministry tweeted.

It added that Poland’s consul in St. Petersburg is in contact with the local authorities and is determining whether any Polish citizens were among the victims.

Russian President Vladimir Putin, who was in St. Petersburg to meet Belarusian leader Alexander Lukashenko, said the cause of the explosion was not yet clear but added that he was taking into account all possibilities, including terrorism.

(pk)