Odessa Police Chief Michael Gerke says that at least 21 people have been injured by gunfire and five killed in a shooting in west Texas.

At a news conference Saturday, Gerke also says that at least three law enforcement officers were among those shot.

He spoke after a chaotic afternoon during which police reported that a suspect hijacked a U.S. Postal Service vehicle and began firing at random in the area of Odessa and Midland, hitting multiple people. Police initially reported that there could have been more than one shooter, but Gerke says authorities now believe it was one shooter.

Gerke says he believes the threat is over but authorities remain vigilant.

Odessa is about 32 kilometres southwest of Midland. Both are more than 480 kilometres west of Dallas.