HOUSTON -- A nightclub owner was killed in the parking lot of his south Houston club early Monday, KPRC Local 2 reported.

Houston police said Rosendo Rios tried to stop a robbery at a mobile taco stand in the parking lot of Mi Ranchito Night Club on Almeda Road near West Orem Drive at about 1 a.m.

Investigators said Rios, 49, was shot in the head after he ran out when the taco stand employee yelled for help.

Rios was transported to Ben Taub Hospital, where he died.

Rios' brother said Rios owned the club for about 10 years and was shot while trying to break up another fight at the club a few years ago.

The club did not have security guards on duty at the time of the slaying.

"I know we had security out here for a while and I guess there was no security last night," brother Leroy Rios said.

The woman working at the taco stand was not physically injured.

The gun and a shell casing were found at the scene, police said.

Police said the gunmen may have been playing pool at the club before the shooting.

Detectives are working to determine if surveillance cameras outside the nightclub were recording when the killing took place.

Investigators said one of the men is white with wavy blond hair, about 6 feet 4 inches tall and weighs about 160 pounds. He was last seen wearing a white T-shirt and shorts.

The second man is black, 20 to 25 years old and 5 feet 2 inches to 5 feet 4 inches tall, police said. He was last seen wearing a black muscle shirt and blue jeans. Witnesses said he had a tattoo across the back of his neck.

The men got away in a dark-colored four-door compact vehicle, police said.

Anyone with information is asked to contact the Houston Police Department Homicide Division at 713-308-3600 or Crime Stoppers at 713-222-TIPS.