Photo: Facebook/Houston Police Department

One suspect and one civilian were killed in Houston on Sunday when at least one gunman began shooting at cars in an apparently random and unprovoked attack, CNN reports. Three bystanders, two police officers and one possible suspect were also wounded, though none of them seriously.

According to witnesses, the attack began when a gunman walked up to a man who had just parked his car at an auto body shop and shot him in the head. From Reuters:

The gunman fired on the first officer to respond to the scene, riddling his car with bullets, including many that struck the windshield, [police spokesperson John] Cannon said. At least five shots also struck a police helicopter, he said.

The officer escaped injury and called for help. A shootout ensued with arriving officers before a SWAT team member shot the suspect dead at about 11:10 a.m., about an hour after police arrived at the scene, Cannon said. Two constables were wounded, not seriously, one struck in the hand and other in his bulletproof chest vest, he said.

A second person, still considered a possible suspect, was also shot, possibly by the primary shooter, Cannon said. He was interviewed at the hospital to give police his version of what happened, Cannon said.

Police say the dead suspect was armed with a pistol and an AR-15 rifle. A motive for the shooting was not immediately clear.

“We do not know what started this,” acting Houston Police Chief Martha Montalvo told reporters, “but what we do know is they were shooting randomly, just at whoever.”