The Navy and Marine Corps in Japan moved Thursday to isolate and track coronavirus cases that have popped up on their installations on Okinawa and just outside Tokyo.

Meanwhile, the governor of Tokyo reported 224 new infections in the metro area Thursday, a surge that exceeded the previous high of 206 on April 17.

For a second time this week, an undisclosed number of people associated with the Marine Corps on Okinawa tested positive for the virus, adding to the number of cases there, according to a Thursday news release from Marine Corps Installations Pacific.

On Okinawa, the Marines on Thursday would not specify how many people tested positive, only that they fell under the status of forces agreement and were on installations that comprise the widespread Marine Corps Base Camp Smedley D. Butler.

This year’s deployment to Darwin, in Australia’s Northern Territory, hasn’t gone as initially planned. Travel restrictions and quarantining requirements due to the novel coronavirus drove the Marine Corps to send a smaller, 1,200-member force for the rotational deployment program, now in its ninth year. That’s less than half the size that deployed in 2019, the first time Marine Rotational Force-Darwin reached its 2,500-personnel maximum.

The deployment will culminate in exercise Koolendong in September with Australian Defence Force units.

The Marines will be in quarantine for two weeks, where they also will be tested twice for the potentially deadly COVID-19 virus.

Just before the newest wave of Marines showed up to Australia, Marines in the first wave of “approximately 200″ Marines were released from the quarantine facility, according to Chuck Little, deputy director of communication strategy and operations for U.S. Marine Corps Forces, Pacific. All Marines in the first wave tested clean from the virus, according to the Marine Corps.

“At the end of the day all it did was delay the deployment a little bit and force us to take a little harder look at how we were going to implement the necessary health protective measures,”

This year’s rotation, delayed by two months due to the coronavirus pandemic, includes 1,200 Marines, fewer than half as many as headed south last year.

Last year, the force brought with it 10 MV-22 Osprey tiltrotors, four AH-1Z Vipers and three UH-1Y Venom helicopters, but the coronavirus meant there aren’t any manned aircraft heading south this time.

The Marines won’t be going to sea on Australia’s amphibious ships HMAS Canberra and HMAS Adelaide, as they did last year, he said.

“It’s the first time for the rotational force to incorporate unmanned aircraft,”

The modified rotation of US Marines will carry out exercises exclusively at Australian Defence Force training areas in the Northern Territory after undergoing two weeks' quarantine at a Defence base in Darwin.

Defence Minister Linda Reynolds gave approval US Secretary of Defense Mark Esper for the reduced contingent in May.

At the time, she said the approval "was based on Australia's record to date in managing the impacts from COVID-19, as well as strict adherence by deployed US Marines to the mandatory 14-day quarantine and other requirements".

Despite the arrival of US Marines, Australian borders remain closed.

The last confirmed cases of coronavirus attributed to the Northern Territory came on May 1, when two Australian Defence Force personnel, who contracted coronavirus on deployment in the Middle East, were flown to Darwin.