Denver police said an ongoing dispute between two groups led to a southeast Denver nightclub shooting in which one person was killed and eight others were injured early Monday morning, according to Denver police.

Officers responded to reports of a disturbance at Ultra Lounge, 9755 E. Hampden Ave., shortly before 1 a.m. While officers were en route, dispatchers received additional reports that shots had been fired.

Denver Police Department Chief Ron Thomas said during a Monday morning news conference that some of the surviving victims sustained serious injuries.

Investigators believe the violence stemmed from a confrontation between two groups at another event in Aurora earlier in the day, Thomas said. The dispute later carried over to Ultra Lounge, where the groups attended an after-party.

A large crowd was gathered at the nightclub when gunfire erupted, according to police. Investigators believe shots were fired both on the patio and in the parking lot. Detectives believe at least two weapons were used.

Police have not identified any suspects, and no arrests have been announced. Investigators have also not recovered any firearms.

“It’s quite a difficult situation,” Thomas said, noting that detectives have numerous witnesses to interview.

The shooting is the latest serious incident tied to the Hampden Avenue venue.

In March, Denver police investigated a homicide at the same location after officers responded to an assault. The 47-year-old male victim was transported to a hospital, where he later died.

Detectives ultimately arrested three suspects in that case on suspicion of second-degree murder.

The investigation into Monday’s shooting remains ongoing. Anyone with information is encouraged to contact Denver police or Metro Denver Crime Stoppers at (720) 913-7867.