Texas, March 24 -- At least six people were injured early Sunday in a shooting at a nightclub in the Texas city of Houston, an assistant chief of police at the Houston Police Department said.

"Three individuals who had been shot were transported to a local hospital. Additionally, three other individuals were transported by private vehicle to hospital," James Skelton said during a news briefing.

He added that four individuals were in critical condition and undergoing surgery.

"They are in surgery at this time. I do not have any other information. We have officers at the hospital checking on their welfare," Skelton said.

The shooting took place at 3 a.m. local time (08:00 GMT) at an after-hours night club, serving alcohol after 2 a.m., wh...