Media captionUSS Fitzgerald damaged by the crash

It said they will be taken to a Japanese hospital to be identified.

The incident took place some 56 nautical miles (104km) south-west of the Japanese port city of Yokosuka, at about 02:30 local time on Saturday (17:30 GMT Friday).

Japanese broadcaster NHK said the collision led to the flooding of the crew’s sleeping quarters while they were asleep.

USS Fitzgerald crash: In pictures

“The damage was significant,” 7th Fleet commander Vice-Admiral Joseph P Aucoin said. “There was a big gash under the water.” Repairs would take some time to complete, he said.

At a press conference in Japan on Sunday, Vice Adm Aucoin would not confirm how many remains had been found so far. Families of the sailors are being notified, he said.

“This loss is something we all feel,” he said.

Image copyrightREUTERS

Image captionThe collision left a huge gash down the right-hand side of the ship

Marine traffic records suggest the ACX Crystal, a 222-metre (730ft) Filipino-flagged container ship, made a sudden U-turn roughly 25 minutes before the crash. It is not known why it changed course.

Similar records for the USS Fitzgerald are not publicly available.

The Navy ship’s starboard side was heavily damaged in the collision, but the vessel later managed to slowly return to its base in Yokosuka, with the assistance of US navy tug boats.

Image copyrightMARINETRAFFIC.COMImage captionThe ACX Crystal appeared to make a U-turn before the collision, before rapidly adjusting course and setting off to Tokyo

Japan’s coastguard said the ACX Crystal had a gross tonnage of just under 30,000, about three times that of the USS Fitzgerald.

It sustained lighter damage to its port bow.

The Associated Press agency said there were no injuries reported among the 20 Filipino crew members on board the ACX Crystal.

It remains at port in Tokyo.