General manager Marc Cramer said the shipment from a Pasco, Wash., farm also contained a second bomb.

Each bomb was about 8 inches long and 3 inches wide, cylindrical in shape with fins on one end.

Police determined they were dummy military ordnance left over from a time when the military used the farm as a practice bombing range.

The bombs had contained a pyrotechnic charge to create a flash to show bombardiers-in-training where the projectile landed.

"We talked to the farmer and he said they find these all the time," Salem police Lt. Dave Okada said. "They usually pick them out before sending the potatoes on."

Cramer said Kettle Foods has a painstaking inspection process to cull all debris from potatoes.

"We did find a cell phone once," Cramer said. "If it's a muddy day when they're harvesting, everything's covered in mud."