PORTLAND — Portland police shut down a section of Pleasant Street near High Street tonight after several shots were fired.

Authorities said a black Lincoln Town Car with its rear window shattered was seen leaving the scene.

Bill and Diane Clark of Beverley, Mass., said they were walking down High Street to eat dinner at a local restaurant when they heard four or five loud bangs that sounded like firecrackers.

The Clarks said they saw a man inside the car, which was speeding away from Pleasant Street, pulling his arm back from a window as if he had just fired a gun.

Patrons at the Flask, a Spring Street bar, said the car backed across a curb, crushed a street sign across from the bar, and kicked up mud at a parked car before speeding away in the direction of Mercy Hospital.

Portland police have not released any details, including whether anyone was wounded during the shooting.