Isis has claimed responsibility for the bombing of a St Petersburg supermarket that injured 13 Christmas shoppers, including a pregnant woman, with shrapnel.

The Islamic terrorists claim they were behind the blast that rocked the Perekrestok market in northwest St Petersburg on Wednesday (27 December).

The attack left 50 people needing to be evacuated from the busy supermarket which was described by Russian President Vladimir Putin as an "act of terror".

Now, without providing any evidence, the media arm of the terrorists, the Amaq news agency, has declared that Isis where behind the bombing.

Russian police believe that the assailants used a homemade IED packed with explosives with the equivalent of 200 grams of TNT and pieces of metal which had the power to kill dozens.

Putin said following the explosion: "I have instructed the director of the Federal Security Service to act within the framework of the law during detention (of suspected terrorists).

"But if there's a threat to a police officer's life and health, our officers need to act decisively, take no prisoners, kill the assailants on the spot."

The terrorists have claimed responsibility for numerous attacks without providing evidence as they come under strain in the Middle East, where they have lost the majority of the territory they once controlled.

Following the blast, in the Kalininsky district, the Investigative Committee, the nation's top investigative agency, opened a criminal case on the grounds of attempted mass murder.

The Sputnik news agency reported that the Committee believe an improvised explosive device "filled with projectiles" caused the blast.

Local news media reported that only a wall and a cash register inside the supermarket were damaged in the explosion.

In the hours after the explosion it was reported that 10 people were injured, with four taken to hospital, although that figure has since been increased.

Earlier this month it was reported that Putin telephoned US President Donald Trump to thank him after the CIA gave Russian authorities a tip that helped stop several attacks on the city.

In April this year the St Petersburg subway system was bombed leaving 16 people dead and injured more than 50 others