A handgun went off during a police safety talk at a kindergarten in the central Chinese city of Zhengzhou, injuring four adults and one child.
The gun misfired during a demonstration and the bullet struck the ground, sending up sparks and cement that hit the arms and legs of bystanders, police said.
The injuries were minor. A police statement said two officers involved were confined as an internal punishment by the department, and that a deputy director, a squad chief and an instructor had been suspended.
Police extended “heartfelt apologies”, it said.
Until recently, few Chinese police carried guns, but the government announced in April more will be issued firearms.
It said they need to respond faster to violent criminals and other emergencies.
China has some of the world’s most restrictive gun laws and prohibits almost all private gun ownership.