A US Navy guided-missile destroyer collided with a merchant ship east of Singapore early Monday, the Navy’s 7th Fleet said in a statement.
The USS John S. McCain collided with the merchant vessel Alnic MC while the destroyer was making its way to a port visit in Singapore, the Navy said.
Search and rescue efforts are under way, the statement said.
Initial reports indicate the US ship sustained damage to its aft port side, the Navy said, but it did not give information on the status of the merchant vessel.
Merchant marine websites describe the Alnic MC as a 30,000 ton, 600-foot long oil tanker flying a Liberian flag.
The McCain is the second US destroyer to be involved in a collision in just over two months.
On June 17, the USS Fitzgerald collided with a container ship off the coast of Japan. That collision resulted in the deaths of seven US sailors.