The attack took place at the Wuxi Vocational Institute of Arts and Technology in Yixing, a smaller city within Wuxi, at around 6:30 p.m. (local time), Yixing police said in a statement.
The suspect, a 21-year-old student surnamed Xu, was detained on the spot.
Police said Wu failed exams and was unable to graduate and was unhappy with his internship salary.
He decided to vent his frustrations with the attack, according to the press release.
Videos circulating on Western social media platforms such as X show injured people lying in the street after the attack, while others rushed to help.
On Chinese social media platforms such as Weibo, keyword searches for the attack show the police statement, but no videos or images related to the attack.
The Chinese government often censors online content if it is deemed overly sensitive or political.
Most Western social media and search engines like Google are blocked behind what is known as the Great Firewall, which regulates what is available inside China.
China has witnessed numerous attacks in which suspects have randomly targeted members of the public.
In October, a man was detained after allegedly attacking children at a school in Beijing with a knife.
Five people were wounded.
In September, three people were killed and 15 injured in a knife attack at a supermarket in Shanghai.
Police said at the time that the suspect had personal financial disputes and had come to Shanghai to “vent his anger”.
The same month, a Japanese schoolboy died after being stabbed on his way to school in the southern city of Shenzhen.