Police work on the site of a knife attack in the center of Surgut, Russia, on Aug 19, 2017. The Islamic State (IS) terrorist group has claimed responsibility for a knife attack that left seven people injured in the central Russian city of Surgut on Saturday, according to media reports.[Photo/Xinhua]

-?The Islamic State (IS) terrorist group has claimed responsibility for a knife attack that left seven people injured in the central Russian city of Surgut on Saturday, according to media reports.

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

Russian authorities have not commented so far.

An attacker stabbed pedestrians while moving along Surgut's main streets at about 11:20 a.m. local time (0620 GMT), and was killed by security forces who had immediately arrived at the scene, according to statements released by Russia's Investigative Committee.

Preliminary information showed that the attacker had been identified as a local resident born in 1994.

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

The regional department of the Russian Interior Ministry said earlier that terrorism was not believed to be the motive for the attack.