A 32-year-old man attacked and injured several people with a knife in front of a driving school in downtown Mainz.
A 48-year-old was critically injured on Tuesday afternoon – at least two other men aged 28 and 48 suffered minor injuries, prosecutors and police reported.
A police officer who had recorded a traffic accident nearby immediately rushed over.
"He was only able to stop the attack by using his firearm and fired several shots," the investigators said in a statement.
The 32-year-old Somali was injured.
With how many shots and how heavy was initially unclear.
He is being watched in the hospital.
The background to the attack is probably a relationship dispute.
There is no evidence of a killing spree or a terrorist background.
Police are investigating an attempted homicide.
The incident happened on Tuesday around 3:10 p.m. at Aliceplatz.
There is no connection with a fatal traffic accident a few hours earlier.
A three-year-old child was hit by a car while crossing a traffic light and was fatally injured.