Dallas police say a U.S. Postal Service worker has been found shot to death inside a mail truck along a busy highway.

Police released a statement Monday saying the case is being investigated as a homicide.

Police say officers found the worker’s body inside the government vehicle early Monday morning after responding to a reported shooting along Interstate 30 near downtown Dallas. The U.S. Postal Service operates two large complexes nearby.

Investigators say no arrests have been made and that they’re still trying to determine a motive in the shooting.

The victim’s name hasn’t been released.

Dallas police and the U.S. Postal Inspection Service are investigating. Inspector Amanda McMurrey had no immediate information Monday about the victim or where the federal employee was traveling.

(AP)