A mass shooting has occurred at a Sikh temple in Oak Creek, Wisc., just outside Milwaukee.
At least four people have been reported injured in the mass shooting and no suspect has been identified. Hospitals in the area were told to be ready for up to 20 shooting victims, according to police radio reports.
"An officer arrived and engaged a suspect. That officer was shot multiple times. He is expected to survive," said Brad Wentlandt, the police chief of Greenfield, Wisc., at a hastily-arranged briefing for news media.
"The officer exchanged fire with the shooter. That shooter was put down."
Some members of the temple are still inside the temple and are hiding, believing that a gunman may still be inside the building.