A dispute at a crowded South Carolina bar early Saturday led to a shooting that left two people dead and nine others injured.

The Lancaster County Sheriff's Office said in a statement that the agency was investigating a shooting at the Old Skool Sports Bar and Grill in Lancaster at about 2:45 a.m.

Two adult males were shot and killed. NBC affiliate WIS News in Columbia identified them as Henry Lee Colvin, 29, and Aaron Harris, 28.

Four injured victims were airlifted to medical facilities for treatment. And four other people were treated at local facilities for injuries considered noncritical.

An eleventh victim was treated and released for minor injuries incurred after falling down while trying to flee.

Old Skool Sports Bar and Grill in Lancaster, N.C. Google Maps

A sheriff's office spokesman called the shooting a "local incident" and told NBC News that an initial investigation revealed that the suspected shooter and one of the victims had an ongoing dispute.

The feud involved one of the men killed, a sheriff's department official said at a press conference Saturday afternoon. The official said he believes the shooter was targeting only the man he was fighting

As of Saturday afternoon no arrests had been made. Authorities said they had leads on a suspect and were trying to locate him.

"This was a violent incident of huge magnitude that was witnessed by lots of people," Sheriff Barry Faile said in a statement. "Two people are dead, and many more are seriously injured. The shooter or shooters are out there. We need to talk with everybody who was at the club when the shooting happened, and I encourage those witnesses to contact us immediately so those responsible for these deaths and injuries can be taken into custody."

The statement says a large crowd was at the Old Skool Sports Bar and Grill when the shooting occurred and that shots were fired inside and outside the bar. Most patrons scattered as shots were fired and afterward.

Lancaster is about 45 miles south of Charlotte, North Carolina.