HOUSTON (CBSDFW.COM/AP) — Authorities are searching for a gunman in Texas who hid on a rooftop and opened fire on a carload of people. Police say the man, who was armed with a rifle, killed two people and injured two others in east Houston.

Police Chief Art Acevedo says the gunman ambushed the group Thursday as they arrived to settle “a score from a previous fight” with another group.

He says the suspect opened fire from the roof of a home abandoned after Hurricane Harvey, killing a 21-year-old man and an 18-year-old man. Another wounded man was taken to a hospital in critical condition. An 18-year-old woman was struck in the knee.

Acevedo says the gunman used an “AR-15-type rifle” with a 30-round clip. Investigators continue to search for the suspect.

Acevedo says the “coward shot these young people like they were deer.”

Police are looking through surveillance video from homes in the neighborhood as they continue searching for the gunman.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)