HARTFORD, Conn. — Gunfire erupted at a Connecticut nightclub early Sunday morning, killing a man and wounding four other people, police said.

A 28-year-old man died in the shooting at the Majestic Lounge in Hartford’s South End, police Lt. Paul Cicero said. Two other males and two females were wounded, with two of them in surgery Sunday morning and two in stable condition, he said. None of their names were released.

Police officers had been stationed outside the club because of previous problems there and reported the shooting at about 1:30 a.m. Officers rushed in, but were confronted with a large number of people running toward the exits, Cicero said.

“Everybody started pushing their way out to get away from the gunfire,” he said. “It was kind of pandemonium.”

Officers, however, were able to provide immediate medical care to the victims, he said.

There were no suspects in custody. Officials said there was little information to release because the investigation was in the very early stages.

A message seeking comment was left Sunday at a phone number for the club.

Mayor Luke Bronin said Sunday that illegal handguns were involved in the shooting. He said there have been problems at the nightclub in the past, but nothing in recent weeks.

City officials will be assessing what steps they can take to prevent violence at the club in the future, Bronin said.

“Hartford Police Officers who were at the club responded immediately, running in the direction of gunfire, and their heroic efforts may have prevented further loss of life,” Bronin said in a statement.

Streets around the club were closed for hours during the emergency response and investigation. Officials left the scene around 7 a.m.

“We’re not going to have anything for quite a bit of time,’ Cicero said, responding to a question about when more information will be released. ”This is a very complex investigation.”