Three World War I-era 25-pound Cooper bombs intended to be dropped from airplanes were among six pieces of unexploded ordnance dug up this week from the golf driving range at Bellows Air Force Station, officials said.

1st Lt. Robert Howard, a Pacific Air Forces spokesman, said one of the bombs had a fuse and was detonated in place at about 4 p.m. Thursday along with another bomb that was inert and had no explosives.

Demolition experts determined the third bomb was not dangerous.

The detonation of the 25-pound Cooper bomb with the explosives caused little damage even to plywood covering the blast, Howard said. A contractor used RDX, a material that penetrates the bomb and slowly builds up heat to trigger any explosive material contained within, to neutralize the ordnance.

Two 100-pound bombs with no explosives or fuses and a 100-pound training bomb also were found, Howard said. An Air Force explosive ordnance disposal team was sent to Bellows to examine the munitions.

Claudia de Leon, an Air Force representative, said the site is being environmentally remediated after it was used as a clay pigeon shooting range, and that that’s how the ordnance was discovered. It now serves as a golf driving range, officials said.

According to the website www.wwiaviation.com, the United States adopted the British Cooper bomb for standard use during World War I.

The bombs were carried in simple racks under a plane’s wing, often in a cluster of four.

According to the Hawaii Aviation Preservation Society, Bellows was established in 1917 as the Waimanalo Military Reservation and was used as an infantry training area.

During the mid-1930s the Army Air Corps used the area for strafing and as a bombing practice site, the aviation society says on its website. Bellows was among installations attacked by the Japanese on Dec. 7, 1941.

According to the organization, five months before the attack Bellows Field became a separate permanent military post, an accelerated construction program was begun and two-story wooden barracks and a new and larger runway were built.

» Some of the bombs and bomb casings discovered at Bellows Air Force Station were from the World War I era, not World War II, as stated in the original headline for this story. Also, six pieces of unexploded ordnance were found, not seven as was reported.