Moscow, Aug 20 (IANS): The Islamic State (IS) terrorist group has claimed responsibility for a knife attack that left seven persons injured in the Russian city of Surgut, media reports said.

"The attacker in the Russian city of Surgut is an Islamic State soldier," the group said via its official Amaq news agency on Saturday.

Russian authorities have not commented so far, Xinhua news agency reported.

A man, who apparently stabbed passersby on the street at random, was shot dead by police. The attack happened at about 11.20 a.m.

The injured were taken to hospital and two of them were in a critical condition, the state-owned RIA Novosti news agency reported.

Russia's Investigations Committee said it had identified the attacker and was checking his psychological history. He was a local resident born in 1994, it said. No motive has been established yet.

A criminal case has been launched, and investigators are verifying information on the attacker's mental disorders, the committee said.