LIBERTY COUNTY, Texas — Authorities have released suspect images of a man they say killed one person and injured five in a Liberty County, Texas bar shooting on Sunday.

According to the Liberty County Sheriff’s Office, the shooting happened just before 2:30 a.m. at Alas Locas near Cleveland, about 45 miles northeast of Houston.

Investigators said the suspect arrived at the bar around midnight, ordered a drink and stayed at the bar for about an hour before leaving for his van. He then returned to the patio area and opened fire on patrons, LCSO said.

Six people were shot, with one man being pronounced dead at the scene. Officials said two out of the five people injured were taken to hospitals by helicopter in critical condition.

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Officials said the suspect is believed to have acted alone and drove away in a vehicle described as a full-size white van with no windows that had a long scratch on the side.

Based on the number of shell casings collected at the scene by investigators, including Rangers from the Texas Department of Public Safety, Capt. David Myers of the Liberty County Sheriff’s Office said the gunman fired at least 20 shots before fleeing the bar.

A motive for the shooting remains under investigation.

The incident marked the second mass shooting at a bar in the Houston metropolitan area this year.

Anyone with information on his location is urged to contact the Liberty County Sheriff’s Office, 936-336-4500, or Crime Stoppers, 800-392-7867.

ABC News contributed to this report.