YOKOSUKA, Japan — A U.S. destroyer was back in its home port after colliding before dawn Saturday with a container ship four times its size, leaving seven sailors missing.

The USS Fitzgerald, flanked by two tug boats and other support vessels, was listing to its right as it slowly approached the port at the Yokosuka Naval Base, south of Tokyo.

Crew members from the destroyer USS Dewey had helped stabilize the damaged destroyer after it collided with a container ship off the coast of Japan, leaving at least three sailors injured, in addition to the seven missing.

Family members were frantically seeking news, appealing via social media for calls from sailors aboard from the ship as it slowly made its way to its home base.

Rescuers were searching for seven sailors who were thought to have been thrown into the sea or possibly trapped inside damaged sections of the destroyer, said Japanese coast guard spokesman Yoshihito Nakamura. No one on the container ship was reported injured.