The police chief of a Wisconsin city where a gunman opened fire at a Sikh temple says the suspect "ambushed" one of the first officers to arrive at the scene as the officer tended to a shooting victim.

Oak Creek Police Chief John Edwards says the suspect shot the officer multiple times outside the Sikh Temple of Wisconsin on Sunday morning. A second officer then exchanged gunfire with the suspect and fatally shot him.

Edwards says the officer who was ambushed is undergoing surgery at a nearby hospital and is expected to survive.

Police earlier said the officer who was shot had killed the gunman, but released updated information later Sunday afternoon.