The munitions will be destroyed in place today with explosives. Initial X-rays showed the munitions to be filled with liquid and to have unstable fuses that make them unsafe to move.

An additional 138 munitions recovered from the range in recent months are in secured storage at Schofield and will undergo testing. Experts from the 22nd Chemical Battalion's Technical Escort Unit made the identification using a portable isotopic neutron spectroscopy system that uses gamma rays to identify a chemical signature, the Army said.

KHON2 News reported that witnesses to the unexploded ordnance discoveries said the munitions also contain phosgene, which causes lung damage, and the blistering agent mustard.

Kendrick Washington, a Schofield spokesman, said the suspect munitions date to World War I and World War II, but only the chloropicrin has been identified.

"We're looking into the history of the munitions," he said last week. "I can't even speculate why they're here. Obviously, back then the world was a different place."

The technical escort unit has started its assessment of the 138 munitions, which include 4.2-inch mortars; 155mm projectiles; 81mm mortars; 75mm projectiles; 4-inch Stokes Mortars; a Livens Projector; and a 105mm projectile.