An argument that started when a couple brought a dog inside a grocery store Friday night erupted into a shootout that wounded two in Houston’s Chinatown district, authorities said.

Just after 8 p.m., Houston police were notified of a disturbance at a grocery store in the 9800 block of Bellaire, said HPD Lt. Larry Crowson.

As an officer arrived, he heard gunshots and called for backup. Police found two people wounded in the shooting, one a security guard and the other a man in his 20s, Crowson said.

Authorities believe it started when the man and his girlfriend entered the grocery store with their dog.

“The security officer told them the dog wasn’t allowed in the business due to health concerns,” Crowson said. An argument ensued, leading the man and the security officer to exchange gunfire.

The two were taken to a hospital and were in surgery, Crowson said. No one else was injured in the shooting.

An investigation is underway.