Divers found this 5-inch shell on Nov. 26, 2024, in waters where the Naha Military Port replacement facility is expected to be built. (Urasoe city)

CAMP FOSTER, Okinawa — Japanese divers working magnetic surveys for the government at two sites on Okinawa discovered 20 pieces of unexploded ordnance believed to be left over from World War II.

Most recently, divers found a 5-inch shell on Nov. 26 in 52-foot waters where the Naha Military Port replacement facility is expected to be built, a spokesman with Urasoe city’s Disaster Prevention and Crisis Management Division said by phone Monday.

It is the first unexploded ordnance found at the site, he said.

The discovery follows others made recently at the commercial port in Naha city.

Divers discovered another 19 pieces of ordnance underwater near Naha Port, a spokesman for the city’s Disaster Prevention and Crisis Management Division said by phone Monday.

In March, divers surveying the area ahead of dredging work found three 276-pound bombs, he said.

Between October and November, divers surveying a different area near the port prior to soil improvement work discovered seven 5-inch bombs, one 4-inch bomb, one 3-inch bomb and seven 81-mm shells, he said.

They are stored “in a safe place within the harbor” and “will be detonated later, most likely in March,” the spokesman said. The shell discovered in Urasoe city is also stored there, he said.

On Friday, disposal experts defused and relocated two WWII-era bombs discovered in October on an island southwest of Okinawa.

Soldiers with the Japan Ground Self-Defense Force’s 101st Explosive Ordnance Disposal Unit defused the 551-pound bombs on Miyakojima, a popular tourist spot 170 miles southwest of Okinawa, a spokesman with the island’s Disaster Prevention and Crisis Management Division said by phone Monday.

The bombs were discovered Oct. 8 and 11 on property next to Miyako Airport. They were relocated to an underground bunker roughly 20 feet deep and 10 feet wide and defused there, the spokesman said.

“Everything went smooth and safe” without affecting the airport or traffic, he said.

The defused bombs are stored in a warehouse managed by Okinawa prefecture until they’re disposed of, the spokesman said.

Magnetic surveys began at Miyazaki Airport on Kyushu in October and are expected to finish in January, a spokesman for the Ministry of Land, Infrastructure, Transport and Tourism said last month.

The surveys came after a 500-pound, WWII-era device exploded Oct. 2 underneath a taxiway shoulder at the airport on the southernmost of Japan’s four main islands.

Preparations are underway for magnetic surveys at other Japanese airports, including Naha Airport on Okinawa, the ministry spokesman said.

Some Japanese officials are required to speak to the media only on condition of anonymity.

Crews disposed of nearly 22 tons of unexploded ordnance between April 1, 2023, and March 31.