Four people were killed and several others were injured after at least one gunman fired into a Birmingham, Alabama, nightclub where a birthday party was being held Saturday night, police said.

Police responded to reports of people shot on 27th Street North at around 11:08 p.m., Birmingham police spokesman Truman Fitzgerald said in a video statement.

One man was found fatally shot on the sidewalk outside the nightclub, two women were found dead inside, and a man taken to a hospital was pronounced dead there, Fitzgerald said.

Ten other people who were shot were being treated at UAB Hospital, police said. Some were taken there by the Birmingham Fire Department and others arrived in private vehicles.

“At least one suspect drove by in a vehicle and fired shots from the street into the nightclub,” police said in a statement.

There was some type of altercation at the club, police said, but detectives are trying to determine if that is connected to the shooting.

There have been no arrests, and police asked the public for any information.

Birmingham police on Sunday identified those killed as: Lerandus Anderson, 24; Stevie McGhee, 39; Markeisha Gettings, 42; and Angela Weatherspoon, 56.

McGhee was found dead outside the business. Gettings and Weatherspoon were killed inside, and Anderson was pronounced dead at the hospital, police said.

Federal law enforcement agencies are also assisting Birmingham police in the investigation, police said.