* John S. McCain warship collides with Alnic MC
* Ten US sailors missing, five injured - Navy
* Sleeping berths flooded, hole below waterline
* Some damage to tanker but no oil spilled - crew member
* Collision is second involving US warship in two months
Ten US sailors were missing after a collision between a destroyer and a tanker east of Singapore on Monday, the second involving a US warship and a merchant ship in Asia in about two months, triggering a fleet-wide probe of operations and training.
The guided-missile destroyer John S. McCain and the tanker Alnic MC collided while the warship was heading to Singapore for a routine port call. The collision tore a hole in the warship's waterline, flooding compartments that included a crew sleeping area, the US Navy said in a statement.
"Initial reports indicate John S. McCain sustained damage to her port side aft," the Navy said. "There are currently 10 sailors missing and five injured."
US Defense Secretary James Mattis said there would be a wider investigation into US naval operations after the collision.
Admiral John Richardson, the chief of naval operations, said he was calling an "operational pause" in US fleets worldwide "to make sure that we are taking all appropriate immediate actions to ensure safe and effective operations around the world."
In a video statement, Richardson said a comprehensive review would "examine the process by which we train and certify our forces that are forward deployed in Japan to make sure we are doing everything we can to make them ready for operations and warfighting."
He said it would include looking at "operational tempo, trends in personnel, material, maintenance and equipment."
He said the review would be conducted on "a very tight timeline" and added: "we need to get to the bottom of this."
The John S. McCain's sister ship, the Fitzgerald, almost sank off the coast of Japan after colliding with a Philippine container ship on June 17. The bodies of seven US sailors were found in a flooded berthing area after that collision.
The US Navy said last week it had removed the two senior officers and the senior enlisted sailor on the Fitzgerald following an investigation into that collision.
The John S. McCain had made its way to Singapore's Changi Naval Base by Monday afternoon under its own power.
Significant damage to the hull had resulted in flooding to compartments, including crew berthing, machinery, and communications rooms, the Navy said, but crew members were able to stop the flooding.
A search-and-rescue mission involving Singaporean ships, helicopters and tugs as well as US Navy aircraft was underway for the missing sailors.
Four of the injured were taken to a hospital in Singapore with non-life threatening injuries. The fifth needed no further treatment.