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.

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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.

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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.

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