CHICAGO (AP) — A Chicago Fire Department paramedic treating a patient inside a hospital emergency room narrowly escaped serious injury when a bullet shattered a window and struck his hat, police said.

According to police, a person in an older model green Buick pulled up to Stroger Hospital on Chicago's near West Side and opened fire at about 10:30 p.m. on Saturday before speeding off.

The bullet struck the bill of the paramedic's baseball-style hat and the paramedic was not injured.

No arrests have been made as of Sunday morning, police said.

The incident happened about 24 hours after a Chicago police officer was shot in the leg on the city's South Side. The 30-year-old officer who was shot while she and her partner got out of their squad car to render aid to a man who was lying in the street, was treated at an area hospital and released on Saturday.

No arrests have been made in the shooting of the officer, who police said was the 12th member of the department to be shot this year and the 46th to be shot at or shot.