Two people have been killed in a shooting at an off-campus Texas A&M University-Commerce party that also left at least 14 others injured, a sheriff's official said.

The shooting took place just before midnight on Saturday in Greenville, around 15 miles (24 kilometres) southwest of the Commerce campus, Chief Deputy Buddy Oxford of the Hunt County Sheriff's Office said. The shooter remains at large, Oxford said.

He said the shooting began around 15 minutes after deputies arrived outside the venue, responding to reports of illegal parking. Deputies heard gunshots coming from the back of the building, but could not tell whether the shots were fired from inside or outside, Oxford said.

Officers found the two people who had been killed inside the building, he said, and 14 others sought treatment of were hospitalised for various injuries. He didn't have a description of the shooter, for whom officers were still searching early Sunday morning.

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Oxford did not have information on the severity of injuries. Medical City Plano spokeswoman Melissa Sauvage told The Associated Press that the hospital had received three victims of the shooting, all of whom were in critical condition. The hospital is around 50 miles (80 kilometers) west of Greenville.

The shooting came as the university east of Dallas celebrated homecoming weekend. The event was a homecoming party, but wasn't a school-sanctioned event, Oxford and university officials said. The chief deputy said officers at the scene estimated at least 750 people were at the party.

The sheriff's office plans to hold another press conference at 8am on Sunday.