A knifeman attacked passers-by in Surgut, Russia Saturday morning leaving eight in serious condition. Police shot the assailant dead and are investigating the background of the would-be murderer.

Russian news agency TASS reports police believe the attacker was suffering from a “mental disorder” as he attacked pedestrians apparently at random. Russian police said in a statement: “an unidentified man ran along the city’s central streets and stabbed pedestrians, injuring eight”.

The assailant was shot dead by an attendant police officer.

Surgut, a comparatively large Siberian city 1,700 miles East of Moscow is home to a number of power plants, as well as oil and gas processing plants.

The stabbing comes as security services around the world remain on high alert after a quick succession of knife and vehicle attacks. Spain saw three attacks in quick succession between Thursday and Friday, as radical Islamists drove a van into crowds of people in central Barcelona, killing 14. This was followed by two further vehicle attacks in which only the attackers were killed.

On Friday, Finland saw two killed and several injured after a knife attack which is now being treated as terrorism.