PINOLE -- Acting on a tip from the FBI, police said they arrested a man Sunday who had allegedly threatened to explode a bomb loaded with nails, bullet slugs, gunpowder and birdshot.

No one was injured.

Philip Penn, 37, of Pinole, was arrested about 9 p.m. in a trailer in the driveway of a home on the 2200 block of Simas Avenue, police said. Police surrounded the home and used a loudspeaker to order Penn to surrender, which he did without incident.

The Walnut Creek Bomb Squad and Pinole police searched the trailer and found the bomb inside. The bomb squad defused the device.

Penn was taken to County Jail in Martinez, where he was held on $500,000 bail on suspicion of possession of a destructive device or explosive.

It was not immediately clear if Penn had a specific target in mind. A spokespersom for the FBI could not immediately be reached.

Contact Daniel M. Jimenez at 510-262-2728. Follow him at Twitter.com/DMJreports.