At least eleven people have died following a blast in St. Petersburg’s underground system on Monday, with many more injured.
The explosion happened between the stations of Sennaya Square and Technology Institute near the centre of the city in Russia.
Authorities have said that the cause of the blast was a suicide bomber, who is thought to have connections with radical Islamists.
Another bomb was successfully deactivated in Vosstaniya Square station. The device, which resembled a fire extinguisher was filled with shrapnel and had the power to do three times the damage of the first bomb.
President Putin expressed condolences to the families of those who died.