Russian officials say a knife-wielding man stabbed and wounded eight people on a central street in the Siberian city of Surgut before police shot and killed him.

A statement from the regional branch of the Investigative Committee said the motive for the mid-day attack Saturday had not been determined. Four of the wounded were in serious condition, state news agency Tass reported, citing regional health official Vladislav Nigmatulin.

Surgut, with aa population of about 320,000, is an oil- and gas-producing center 2,100 kilometers (1,300 miles) northeast of Moscow.