This story was updated with a new statement from U.S. 7th Fleet.

Ten sailors are missing after a U.S. guided-missile destroyer collided with a chemical tanker in the South China Sea near Singapore, a Navy official told USNI News on Sunday.

USS John McCain (DDG-56) collided with the Liberian-flagged chemical tanker Alnic MC around 5:24 a.m. on Monday local time. The ship is now underway on its own power and heading into port in Singapore at the Changi Naval Base. Five sailors were injured in addition to the ten that are missing.

“Four of the injured were medically evacuated by a Republic of Singapore Navy Puma helicopter to a hospital in Singapore for non-life threatening injuries,” U.S. 7th Fleet said.

“The fifth injured sailor does not require further medical attention.”

The crew is fighting flooding in several spaces on the ship, a Navy official told USNI News on Sunday night. The ship has limited propulsion and electrical power but good communications as it heads back into port. The big deck amphibious warship USS America (LHA-6) is steaming toward McCain to offer support to the stricken destroyer.

“Initial reports indicate John S. McCain sustained damage to her port side aft,” read a statement from U.S. 7th Fleet.

“The extent of damage and personnel injuries is being determined. The incident will be investigated.”

According to U.S. 7th fleet, Singapore Navy SS Gallant (97), RSN helicopters and Police Coast Guard vessel Basking Shark (55) are rendering assistance.

MV-22s and MH-60s from the America Amphibious Ready Group are also responding to the incident.

The collision of McCain follows the June 17, collision between destroyer USS Fitzgerald (DDG-62) and the merchant ship ACX Crystal. On Thursday 7th Fleet commander announced punishments for several crew members who were on duty when the early morning collision occurred.

Earlier this month, the destroyer conducted a freedom of navigation operation past the Chinese artificial island on Mischief Reef.

Destroyer McCain is part of the U.S. forward-deployed naval forces based in Japan. The ship is named for the former U.S. Pacific Command Commander Adm. John S. McCain Jr.

The following is the complete statement from 7th Fleet.

SOUTH CHINA SEA – The guided-missile destroyer USS John S. McCain (DDG 56) was involved in a collision with the merchant vessel Alnic MC while underway east of the Straits of Malacca and Singapore on Aug. 21. There are currently 10 Sailors missing and five injured. Four of the injured were medically evacuated by a Republic of Singapore Navy Puma helicopter to a hospital in Singapore for non-life threatening injuries. The fifth injured Sailor does not require further medical attention. The collision was reported at 6:24 a.m. Japan Standard Time, while the ship was transiting to a routine port visit in Singapore. The ship is currently sailing under its own power and heading to Changi Naval Base. At this point, no fuel or oil is visible on the water’s surface near the ship. Search and rescue efforts are underway in coordination with local authorities. In addition to tug boats out of Singapore, RSN Fearless-class patrol ships RSS Gallant (97), RSS Resilience (82), RSN helicopters and Singaporean Police Coast Guard vessel Basking Shark (55) are currently in the area to render assistance. An MH-60S helicopter from the amphibious assault ship USS America (LHA 6) is in the area providing search and rescue assistance. An additional MH-60S helicopter and MV-22 Osprey are expected to arrive soon. Alnic MC is a Liberian-flagged 600-foot oil and chemical tanker with a gross tonnage of 30,000. Initial reports indicate John S. McCain sustained damage to her port side aft. Damage control efforts continue while the extent of damage is being determined. The incident will be investigated.