Police in Houston say six people were shot and injured after someone opened fire in a crowded parking lot outside of a club in Houston early Sunday.

Police Chief Troy Finner said officers found six people shot following a disturbance inside the club that spilled out into the parking lot. Finner said one of the six victims is in critical condition and underwent emergency surgery. The victim’s prognosis was uncertain. The other five victims are expected to survive.

No suspects have been arrested. Finner says surveillance video taken at the scene would be reviewed as part of the investigation.