Federal and local police Tuesday were investigating an explosion that destroyed a pickup truck in the Avenues early Monday.

The 1976 Ford truck was parked at the rear of an apartment building at 275 L St. The owner discovered the damage about 8 a.m., although neighbors said they heard an explosion about four hours earlier, said Salt Lake Police Lt. Joel Campbell.Campbell said it was not clear what type of device was used. "It was definitely a high explosive, though."

The blast blew out the windshield and the doors of the vehicle, Campbell said.

The truck's owner told police he has no idea who set off the device.