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.