BEIJING (AP) — A knife attack at a supermarket in Shanghai killed three people and injured 15 others, local police said.

A 37-year-old man surnamed Lin was taken into custody by police responding to the report of the attack Monday evening, the local Songjiang police branch said in a statement Tuesday.

Eighteen people were sent to hospital for treatment, and three later died.

Police said Lin had personal financial disputes and came to Shanghai to “vent his anger,” and that further investigation is underway.

The attack took place in a suburban district southwest of Shanghai and comes on the eve of the weeklong National Day holidays.

Several knife attacks have occurred in China this year.

Last month, a 10-year-old Japanese student died after being stabbed near his school in southern China. This follows another knife attack at a school bus stop for a Japanese school that killed a Chinese national who tried to stop the attacker, and injured a Japanese mother and child.

Earlier this year, a Chinese man stabbed four U.S. university instructors at a public park in Jilin in the northeast and a Chinese person who tried to intervene. The four instructors from Cornell College were teaching at Beihua University. Their injuries were not critical.