Three people were killed early Sunday during a shooting at a bar in the US city of Austin, Texas, which the FBI said may have been an "act of terrorism."

Fourteen others were wounded, including three who were in a critical condition.

The gunman, who has not been identified, was among the dead.

Speaking at a press conference, Austin Police Chief Lisa Davis said police received reports of a "male shooting at Buford's" Backyard Beer Garden, a popular bar in the city's entertainment district.

When police arrived at the scene, Davis said they confronted a man with a gun and "returned fire, killing the suspect."

Potential act of terrorism

FBI special agent Alex Doran said an exact motive wasn't clear, but there were "indicators" found on the gunman and inside his car that suggest "a potential nexus to terrorism."

"In terms of specifically what type of terrorism, we're just at this point prepared to say that it was potentially potentially an act of terrorism," Doran said.

Davis said the suspect first drove past the bar several times before opening fire from his vehicle. He then parked his car and walked toward the bar, shooting at patrons with a rifle. 

Austin Emergency Medical Services (EMS) Chief Robert Luckritz said three people were found dead at the scene. 

"We received a call at 1:39 a.m. local time (0739 GMT) and within 57 seconds, the first paramedics and officers were on scene actively treating the patients," Luckritz added.

Mayor praises rapid response

Police say they maintain a large presence in the party neighborhood and were able to quickly dispatch officers to the scene as bars in the area were closing.

Austin Mayor Kirk Watson said he was "very thankful for the speed with which our public safety officials responded to this."

"I don't think there's any question that it saved lives," he said.

Edited by: Natalie Muller