Two people were killed and 14 others injured after a gunman opened fire outside a bar in Austin, Texas, early Sunday morning in an attack that U.S. authorities say may have links to terrorism.

The suspect, identified as Ndiaga Diagne, a 53-year-old naturalised U.S. citizen originally from Senegal, was shot dead by police shortly after the attack.

Police said the shooting occurred around 2 a.m. outside a busy nightlife area on West Sixth Street, where the gunman first fired at people from inside his SUV before stepping out and continuing to shoot with a rifle.

Emergency responders transported 14 victims to nearby hospitals, while two people died at the scene.

The U.S. Federal Bureau of Investigation (FBI) said investigators had found “indicators” suggesting a possible terrorism connection, but stressed that the motive remains under investigation.

Law enforcement sources said the suspect was wearing clothing bearing Islamic messages and symbols linked to Iran at the time of the attack.