Japanese soldiers disarm World War II-era ordnance in Naha city, Okinawa, Sept. 29, 2024, in this screenshot from a Japan Ground Self-Defense Force video. (Japan Ground Self-Defense Force)

CAMP FOSTER, Okinawa — Japanese troops successfully disarmed and removed a suspected World War II-era bomb from Okinawa prefecture’s capital city Sunday, according to city and military officials.

The 551-pound, unexploded ordnance was discovered Dec. 12 at a sewage system construction site in Naha city’s Shuri district. It was defused and moved to a prefecture storage facility until it is detonated at sea “on a later day,” a spokesman with the Japan Ground Self-Defense Force said by phone Monday.

The operation required the evacuation of 1,400 people in 470 households and 80 businesses within a 928-foot radius of the bomb, according to the city’s website.

Members of the Ground Self-Defense Force’s 101st Explosive Ordnance Disposal Unit began the operation at 10:45 a.m., 45 minutes later than scheduled due to the evacuation taking more time, a spokeswoman with Naha’s Disaster Prevention Division said by phone Monday.

A hole 16 feet deep was prepared to accommodate the shell’s removal from a narrow site in a heavily populated area, the spokeswoman said. Troops used a crane to move the shell into the hole, then defused it and carried it away, she said.

The operation concluded at 11:55 a.m., the spokeswoman said.

“It just took a little bit of time to start, but the operations finished without any problem,” she said.

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

City and fire department officials announced the evacuation plan in August.

Approximately 2,000 tons of ordnance remains undiscovered out of 10,000 tons dropped on the island during the Battle of Okinawa, according to the prefecture’s General Bureau website.

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

In June, authorities detonated three shells believed to be left over from World War II on an island just southeast of Naval Base White Beach.

“We will continue ordnance removing operations to ensure the safety of citizens,” the Ground Self-Defense Force spokesman said.