Three people were killed and 15 others injured in a knife attack at a supermarket in Shanghai, the city's police said on Tuesday.

The suspected attacker, a 37-year-old man surnamed Lin, was arrested at the supermarket shortly after the incident on Monday night, Shanghai police said in a statement.

Officers said the man went on the rampage sparked by a "personal financial dispute".

Eighteen wounded people were taken to hospital, where three died, they added. The other 15 did not sustain life-threatening wounds.

An investigation is underway. (Xinhua/AFP)