BANGKOK — Ten Navy sailors were missing and five were injured on Monday after a United States destroyer collided with an oil tanker off the coast of Singapore, the Navy said, the second accident involving a Navy ship and a cargo vessel in recent months.

The guided-missile destroyer, the John S. McCain, was passing east of the Strait of Malacca on its way to a port visit in Singapore at 5:24 a.m. local time, before dawn broke, when it collided with the Alnic MC, a 600-foot vessel that transports oil and chemicals, the Navy said. The destroyer was damaged near the rear on its port, or left-hand, side.

Ten sailors on the ship were unaccounted for, and five others were injured, a Navy official said. Ships with the Singapore Navy and helicopters from the assault ship America were rushing to search for survivors. Four of the injured were transported by a Singapore military helicopter to Singapore, where they were being treated for conditions that were not believed to be life-threatening. The fifth injured sailor did not require additional medical attention, according to the Seventh Fleet.

While the collision involved a Navy vessel and a commercial tanker, the incident highlighted the geopolitical dangers surrounding the South China Sea, where China has been challenging American naval dominance. It also raised questions about the safety record of Navy ships, since the incident came just two months after seven people were killed when another Navy destroyer collided with a freighter off Japan.