A person opened fire in a busy entertainment district in downtown Austin early Saturday, wounding 13 people, including two critically, before getting away, authorities said.

Investigators were looking into what sparked the shooting and weren’t able to get a detailed description of the shooter, but they believe it was a man, Police Chief Joseph Chacon said at a 4 a.m. news conference. He said investigators were examining surveillance video and other evidence, and he asked anyone with information about the shooting to contact the police.

The gunfire erupted just before 1:30 a.m. along 6th Street, a popular area filled with bars and restaurants. At the time, the street was barricaded to keep out vehicle traffic, Chacon said.

Eleven of the wounded were taken to one local hospital and the other two were taken to other hospitals, the chief said.

“Our officers responded very quickly,” the interim chief said. “They were able to immediately begin life-saving measures for many of these patients, including applications of tourniquets; applications of chest seals.”

Some officers drove patients to the hospital because of how chaotic it was at the shooting scene, where it was hard to contain the crowd and get ambulances to the wounded, Chacon said.