UPDATE 9.45am: The USS John S. McCain has docked at Singapore's naval base with "significant damage" to its hull after an early morning collision with an oil tanker as vessels from several nations searched for 10 missing sailors.
The clash east of Singapore between the guided-missile destroyer and the 600-foot Alnic MC was the second involving a ship from the Navy's Seventh fleet in the Pacific in two months.
Vessels and aircraft from the US, Indonesia, Singapore and Malaysia were searching on Monday for the missing US sailors.
Four sailors were evacuated by a Singaporean navy helicopter to a hospital in the city-state for treatment of non-life threatening injuries, the Navy said.
A fifth injured sailor did not require further medical attention.
Ten sailors are missing and five are injured after a US warship collided with an oil tanker near Singapore pic.twitter.com/GXEzk3INLv— The Telegraph (@Telegraph) August 21, 2017
The McCain had been heading to Singapore on a routine port visit after conducting a sensitive freedom-of-navigation operation last week by sailing near one of China's man-made islands in the South China Sea.
The Navy's Seventh Fleet said in a statement that damage to the McCain's hull flooded adjacent compartments including crew berths, machinery and communications rooms.
A damage control response prevented further flooding, it said.
The destroyer was damaged on its port side aft, or left rear, from the collision but headed to port under its own power.
A photo tweeted by Malaysia's navy chief Ahmad Kamarulzaman Ahmad Badaruddin showed a gaping hole in the McCain's side near the waterline.
Janes, a defence industry publication, estimated the hull rupture was 10 feet wide.
There were no reports of a chemical or oil spill.
EARLIER: A US navy guided-missile destroyer collided with a tanker early on Monday in waters east of Singapore and the Strait of Malacca, and at least 10 sailors are missing.
The navy said five others were hurt.
The USS John S McCain sustained damage on its port side aft, or left rear, from the collision with the Alnic MC that happened at 5.24am local time, the navy's 7th Fleet said. It was not immediately clear if the oil and chemical tanker sustained damage or casualties in the collision.
The navy said Osprey aircraft and Seahawk helicopters from the USS America were assisting, and tugboats and Singaporean naval and coast guard vessels were in the area to help.
Malaysia's navy chief Ahmad Kamarulzaman Ahmad Badaruddin tweeted that two ships as well as aircraft from its navy and air force have been deployed to help look for the missing US sailors.
The Strait of Malacca is a narrow body of water between Malaysia to the north-east and Indonesia to the southewest, with the city-state of Singapore at the tip of the Malay Peninsula.
The collision is the second involving a ship from the 7th Fleet in the Pacific in two months. Seven sailors died in June when the USS Fitzgerald and a container ship hit each other in waters off Japan.
The Fitzgerald's captain was relieved of command and other sailors were being punished after the navy found poor seamanship and flaws in keeping watch contributed to the collision, the navy announced last week.
An investigation into how and why the Fitzgerald collided with the other ship was not finished, but enough details were known to take those actions, it said.
The Japan-based 7th Fleet said the McCain had been heading to Singapore for a routine port visit when the collision occurred.
The ship is based at the 7th Fleet's homeport of Yokosuka, Japan. It was commissioned in 1994 and has a crew of 23 officers, 24 chief petty officers and 291 enlisted sailors, according the Navy's website.
The warship is 154 metres in length.
The Alnic MC is a 183-metre oil and chemical tanker.
President Donald Trump tweeted: "Thoughts & prayers are w/ our @USNavy sailors aboard the #USSJohnSMcCain where search & rescue efforts are underway."
The destroyer had been heading to Singapore on a routine port visit after last week conducting a sensitive freedom of navigation operation by sailing near one of China's man-made islands in the South China Sea.
Senator John McCain tweeted: "Cindy & I are keeping America's sailors aboard the USS John S McCain in our prayers tonight - appreciate the work of search & rescue crews."
Cindy & I are keeping America's sailors aboard the USS John S McCain in our prayers tonight - appreciate the work of search & rescue crews https://t.co/jzk9giXbfg— John McCain (@SenJohnMcCain) August 21, 2017
The senator is a navy veteran whose father and grandfather were decorated for their actions in the Pacific in the Second World War. Both elder McCains became admirals and the ship is named for them.
Four of the injured sailors were evacuated by a Singaporean navy helicopter to a hospital in Singapore for treatment for non-life threatening injuries, and one did not require further medical attention.