Four people have died and more than 20 were wounded in a shooting in a nightlife area in the U.S. state of Alabama, according to police and news reports.

There were multiple people shot in Birmingham, the Birmingham Police Department said in a social media post.

Birmingham Officer Truman Fitzgerald said the shooting, with up to 21 people wounded, happened shortly after 11 p.m., AL.COM reported.

Fitzgerald said there were "dozens of gunshot victims" and at least four had "life-threatening" injuries, AL.COM reported.

Birmingham Fire and Rescue Service pronounced the three victims dead on the scene and a fourth person was pronounced dead at University of Alabama at Birmingham Hospital, AL.COM reported.

Police said the victims found dead at the scene included two men and a woman, WBMA-TV reported.

Other victims were transported to hospitals in private vehicles, police told WBMA.

The Birmingham police did not immediately respond to an email from The Associated Press seeking additional information.

The Five Points South area of Birmingham has numerous entertainment venues, restaurants and bars and often is crowded on Saturday nights.

Police said there were no immediate arrests.

"We will do everything we possibly can to make sure we uncover, identify and hunt down whoever is responsible for preying on our people this morning," Fitzgerald told WBMA.