Four people were killed and dozens injured in a mass shooting Saturday night in Birmingham in the U.S. state of Alabama, according to U.S. media reports.

Birmingham police reported that the shooting occurred in a busy neighborhood on the 2000 block of Magnolia Avenue, in the Five Points South area near the University of Alabama. Three victims were pronounced dead at the scene, and a fourth died later at the university's hospital. Several others sustained serious injuries.

Authorities believe multiple gunmen were involved in the shooting. As of early Sunday morning, no suspects had been apprehended.

According to statistics from the Gun Violence Archive website, the incident extends the list of at least 403 mass shootings across the United States so far this year. The archive defines a mass shooting as one in which at least four people are killed or injured, excluding the shooter.

(With input from Xinhua)