Seven people were also injured in the attack in Kaiyuan City, Liaoning Province, state broadcaster CCTV reported.
A single suspect named Yang has been arrested and police are investigating the case, the Kaiyuan municipal public security office said in a statement.
Police did not mention the motive for the attack or details about the suspect or the victims. CCTV reported that one of the police officers who helped subdue the suspect was among the injured.
A video posted by the state of Beijing News on Chinese social media showed two police officers (one of them with a broom) confronting the suspect and attacking him on the ground.
Public knife attacks are not uncommon in China.
In June, 37 children and two adults were injured by a knife attacker at an elementary school in southwestern Guangxi region.
In October 2018, a woman carrying a kitchen knife cut at least 14 children in a kindergarten in central Chongqing city.
Nine students died at a middle school in Shaanxi Province in April 2018 by a 28-year-old man who was later sentenced to death.
In 2017, 11 students were injured after a man climbed over the wall of a kindergarten with a knife and began attacking them.
But perhaps the worst period of stabbings occurred in 2010, which included a period of three consecutive days in which the attackers ran the schools. The Chinese Ministry of Education responded to these facts by ordering schools to strengthen security and prevent strangers from entering campuses.