Ten US sailors were missing and five injured after their destroyer collided with a tanker east of Singapore early Monday, the second accident involving an American warship in two months.

The guided-missile destroyer USS John S. McCain arrived in Singapore Monday afternoon with a large hole torn in its hull after the pre-dawn accident sent water flooding into the vessel, the US Navy said.

A major search involving ships and aircraft from three countries was launched for the missing sailors after the warship collided with the Alnic MC near the Strait of Malacca.

"Significant damage to the hull resulted in flooding to nearby compartments, including crew berthing, machinery, and communications rooms," the navy said in a statement, after the vessel arrived at Changi Naval Base in the city-state.

"Damage control efforts by the crew halted further flooding."

A helicopter took four of the injured to a Singapore hospital with injuries that were not life-threatening while the fifth did not need further medical attention, the navy said.

The 505-foot (154-metre) vessel could still sail under its own power after the collision with the Liberian-flagged tanker at 5:24 am (2124 GMT Sunday), which was slightly bigger at 600 feet (182 metres). Two other vessels escorted it into port, AFP journalists saw.

The warship had been heading for a routine stop in Singapore after carrying out a sensitive "freedom of navigation operation" in the disputed South China Sea earlier in August, sparking a furious response from Beijing.

The vessel is named after US Senator John McCain's father and grandfather, who were both admirals in the US navy.

McCain said in a tweet that he and his wife "are keeping America's sailors aboard the USS John S McCain in our prayers tonight -- appreciate the work of search & rescue crews".

President Donald Trump initially said "that's too bad" in response to reporters' shouted questions about the collision, as he arrived back at the White House after a holiday.

He followed up with a Tweet: "Thoughts & prayers are w/ our sailors aboard the where search & rescue efforts are underway."

In June seven American sailors died when the destroyer USS Fitzgerald collided with a Philippine-flagged cargo ship in a busy channel in Japan.

- Air-sea search -

After Monday's incident Singapore sent three tugboats and four navy and police coastguard vessels, neighbouring Malaysia deployed eight ships and was set to send out aircraft, while US aircraft were also involved.

The ship involved in the accident was a tanker used for transporting oil and chemicals and weighed over 30,000 gross tonnes, according to industry website Marine Traffic.

It sustained some damage but no crew were injured, Singapore's Maritime and Port Authority said. There were no reports of oil pollution and sea traffic in Singapore waters was unaffected.

The June collision happened in a busy channel not far from Yokosuka, a gateway to container ports in Tokyo and nearby Yokohama.

The dead sailors, aged 19 to 37, were found by divers in flooded sleeping berths a day after the collision tore a huge gash in the side of the Fitzgerald.

A senior admiral announced last week that the commander of the destroyer and several other officers had been relieved of their duties aboard their ship over the incident.

On August 10 the John S. McCain sailed within six nautical miles of Mischief Reef -- an artificial island built by Beijing in the South China Sea, which forms part of the disputed Spratly Islands.

The foreign ministry in Beijing said it was "strongly dissatisfied" with the move, the latest by the US aimed at easing the Asian giant's grip on the strategic waterway.

Both the USS John S. McCain and USS Fitzgerald are part of the US Seventh Fleet based in Yokosuka.

source: AFP