TOKYO — Seven crew members were missing and at least two, including the captain, were injured after a US Navy destroyer collided early Saturday morning with a merchant ship off the coast of Japan, the Japanese Coast Guard reported.

Footage from the Japanese TV network NHK showed heavy damage to the mid-right side of the Navy ship, which appeared to be stationary in the water, and a person in a stretcher being lifted to a helicopter.

The US Seventh Fleet said on its Facebook page that it was working with the Japanese Coast Guard to conduct a medical evacuation for a sailor.

The Seventh Fleet said in a statement another injured person was being evacuated but gave no further details on the crew’s injuries. Others hurt in the crash were being evacuated, it said. The fleet said the number of injuries is still being determined.

‘‘Right now we are focused on two things: the safety of the ship and the well-being of the sailors,’’ said Admiral Scott Swift, commander of the US Pacific Fleet.

The Navy, Japanese maritime defense vessels, and the coast guard were working to stabilize the destroyer as it went to shore, said Navy Chief Admiral John Richardson.

The Japanese Coast Guard said it received an emergency call from a Philippine-registered container ship ACX Crystal at around 2:20 a.m. that it had collided with the USS Fitzgerald about 12 miles southeast of the Irozaki cape.