Police in northern China say 18 people were injured when a man attacked people on a city street with a knife.

The Changchun police department said on its microblog that the 50-year-old suspect in Tuesday's attack was taken into custody after being shot.

It said none of the injuries were life-threatening and officers were looking further into any possible motivations. The police microblog cited family members as saying that the suspect, Wang Yunwei, had formerly been hospitalized for mental health issues.

China has seen numerous such incidents usually blamed on people with mental health issues or who bore grudges against their neighbors or society as a whole.

Because Chinese law tightly restricts the sale and possession of firearms, mass attackers generally use knives or homemade explosives.

Many of those incidents have occurred at schools, dating back to a series of attacks in 2010 in which nearly 20 children were killed, prompting a response from top government officials and leading many schools to beef up security. Last year, a knife-wielding assailant injured seven students outside a primary school in a northern city.