Two officers were wounded in a Washington Heights shooting when the passenger of a car opened fire on them during a traffic stop Friday night, police said. View Full Caption Getty Images/Keith Levit

CHICAGO — Two officers were wounded in a Washington Heights shooting when the passenger of a car opened fire on them during a traffic stop Friday night, police said.

"Aside from being nuts, I don't know why" the gunman shot at the officers in the 9300 block of South Wallace Avenue, said Pat Camden, spokesman for Chicago's police union.

The passenger and the car's driver were also wounded in the incident that occurred at 11:30 p.m., according to a police statement.

Officers were approaching the car when the male passenger fired at them from inside the car.

A 38-year-old officer was shot in his leg and taken to Advocate Christ Medical Center in Oak Lawn where he is in good condition.

A bullet pierced a 31-year-old officer's bulletproof vest. That officer was taken to Christ and has since been released.

The male passenger, whose age and injuries aren't available, was taken to Christ. The female driver was taken to Little Company of Mary Hospital in Evergreen Park.

Camden said a gun and shell casings were recovered from the scene.