A man was shot in the head moments after he sang a song during karaoke night at a southwest Houston restaurant, police said.

The shooting happened at Ostioneria Mazatlan, a Mexican-seafood restaurant, at 2 a.m. Monday in the 6400 block of Hillcroft near Westward.

Police said the victim was with his family. A restaurant employee said that after the victim sang, he screamed that he was from Guerrero, Mexico.

"Apparently, it was karaoke night. One of the gentleman, as soon as he stepped off the stage, someone didn't agree with the song or the music or something, and there was an altercation inside the restaurant," said J.J. Wilson with HPD Homicide.

An employee said a shouting match could be heard across the restaurant.

"(The shooter) told him to shut up (and said) 'Why are you screaming the name of that town?'" the employee said. "(The victim) said, 'Why? It's my town.'"

Police said the victim was then shot in the head.

Nelly Hernandez said she was friends with the victim and often went to the restaurant with him. She said she is shocked by the shooting.

"He play with the music," said Hernandez.  "He joke all the time. He friends with everybody." 

Detectives said they need help to identify and find the shooter.

"There was one shooter and several other men who ran out with him and jumped in a red Chevy pickup truck and fled northbound on Hillcroft," Wilson said.

The suspect was described as in his 20s. Two women were also with the gunman before he fled, police said. The women drove off in a green Nissan Pathfinder.

Six employees and customers were inside the restaurant when the shooting occurred. No one else was hurt.

Employees said there have been several fights inside the restaurant recently.

Anyone with information about the case is asked to call Crime Stoppers at 713-222-TIPS.