MARTINEZ, Calif. (AP) _ A man was killed when a bomb he was apparently trying to put under a parked truck exploded prematurely, breaking windows and strewing body parts along the street, officials said.

No neighborhood residents were injured in the blast at 5:30 a.m. Saturday, said Sgt. Jim Hatchell, a Contra Costa County Sheriff's Department spokesman.

The man, whose name was not being released until relatives could be notified, apparently was trying to put the bomb under a truck parked on the street when it went off in his hand, Hatchell said.

Investigators had no report about possible motive for the incident about 30 miles east of San Francisco.

''It was a scary thing,'' said Chris Heiderick, who woke up at the sound of the blast thinking there had been a fire at a nearby oil refinery.

''I looked to see if there was a fire,'' she said. ''I didn't see anything. But later, when I went outside again, I figured police would tell us to evacuate. But they just said to go inside. I didn't really want to look.''

Heiderick said children in the neighborhood often play in the street. ''If it happened any other time, I can't imagine what would have happened,'' he said.