LEWISTON — Spent shell casings were found in the street and at least one building was struck by bullets Wednesday night after the latest round of gunfire downtown.

At about 7:25 p.m. Wednesday, numerous people called police to report that shots had been fired downtown. Several police officers were on the scene at Walnut and Howard streets within seconds, witnesses said, but no victims or suspects were found.

Witnesses told police they heard a vehicle speed away from the scene following the gunfire.

Some witnesses reported hearing five gunshots. Others said they thought they heard six or more. One man, walking back from a Pine Street store said he heard a dozen shots ring out just blocks away.

For a time, police shut down a section of Howard Street as they gathered evidence and interviewed witnesses.

The building that was struck by bullets is on Walnut Street, police said. The shooting remained under investigation later Thursday.

For at least a year, Lewiston residents have been vexed by frequent gunfire, most of it reported in the downtown area.

In mid-December, a group of what appeared to be masked men exchanged gunfire in the area of Walnut and Birch streets. One man who was hit by gunfire was later charged by police for his role in the shooting.