HOUSTON — A security officer and a man believed to be about 20 years old were critically injured in a grocery store shooting after the customer was told his dog was not allowed inside, police said.

Westside patrol officers responded to a disturbance at the store, Great Wall Supermarket in the 9800 block of Bellaire Boulevard shortly after 8 p.m. Oct. 9. Officers heard gunfire as they arrived, requested backup and found both people wounded.

Police said the man and a woman believed to be his girlfriend had entered the store with a dog. The security officer told them the dog was not allowed inside because of health concerns. An argument followed, during which the man and the security officer reportedly exchanged gunfire.

Officers provided first aid before both were transported to a hospital. Both were undergoing surgery and were in critical condition.

Everyone believed to have discharged a firearm was in custody, police said. No ongoing danger to the public was believed to exist.

The woman and dog were not injured. She remained at the scene for detectives to question her. Officers were seeking surveillance video and awaiting investigators to conduct a follow-up investigation.