TOKYO — Seven American sailors are unaccounted for after a Navy destroyer collided with a merchant ship southwest of Yokosuka, Japan, early Saturday local time, the Navy said.

The USS Fitzgerald, a 505-foot destroyer, collided with a Philippine container vessel at approximately 2:30 a.m. Saturday local time (1:30 p.m. ET Friday), the U.S. 7th Fleet said. The incident occurred about 56 nautical miles off Yokosuka.

The ship, which had experienced some flooding after the collision, was tugged back to Yokosuka Naval Base, south of Tokyo.

USS Fitzgerald arrives at the U.S. naval base in Yokosuka, south of Tokyo. TORU HANAI / Reuters

Meanwhile, search and rescue efforts by U.S. and Japanese aircraft and boats were underway in the area where the vessels collided.

The U.S. Navy said damaged areas of the ship will also be searched after the ship is safely docked.

"Right now we are focused on two things: the safety of the ship and the well-being of the Sailors," Adm. Scott Swift, commander of the U.S. Pacific Fleet, said in a statement. "We thank our Japanese partners for their assistance."

The Fitzgerald’s commanding officer, Cmdr. Bryce Benson, was injured and transported by helicopter to the U.S. Naval Hospital Yokosuka and is reportedly in stable condition, officials said. Two others also suffered lacerations and bruises and were flown by helicopter to the naval hospital, officials added.

The White House said President Donald Trump was briefed on the situation.

An Alabama woman, Rita Schrimsher of Athens, said on Twitter that her grandson was on the ship and is safe. She said she spoke with her 23-year-old grandson Jackson Schrimsher and that "it could have been worse so we're grateful," The Associated Press reported.

The U.S. 7th Fleet said earlier that some flooding was reported on the Fitzgerald, but it remained under its own power although propulsion was limited. Officials said shortly after 2 p.m. Saturday Tokyo time that flooding had been stabilized.

#FITZ UPDATE: Flooding has been stabilized and Sailors from #USSDewey are assisting in damage control efforts. #USSFitzgerald — 7th Fleet (@US7thFleet) June 17, 2017

The Fitzgerald suffered damage to its starboard side above and below the waterline. A U.S. Navy official said after the collision that the bridge was damaged and communication with the ship was limited and difficult.

The damage of the right side of the USS Fitzgerald is seen off Shimoda, Shizuoka prefecture, Japan, after the Navy destroyer collided with a merchant ship, June 17, 2017. Iori Sagisawa / Kyodo News via AP

Adm. John Richardson, chief of naval operations, said in a statement: "As more information is learned, we will be sure to share to it with the Fitzgerald families and when appropriate the public. Thank you for your well wishes and messages of concern. All of our thoughts and prayers are with the Fitzgerald crew and their families."

The USS Dewey and several Navy aircraft will also assist the Japanese Coast Guard and the Japan Maritime Self-Defense Force in the search, the Navy said.

U.S. Naval Forces Japan said an emergency family assistance center was established and families had phone numbers they could call for more information. They added that chaplains and counselors were made available.

"Navy Region Japan and the shore enterprise are 100% committed to providing support to these families during this difficult time," Rear Adm. Greg Fenton, commander of the Naval Forces Japan, said in a statement.

In this photo released by Japan's 3rd Regional Coast Guard Headquarters, the damage of Philippine-registered container ship ACX Crystal is seen in the waters off Izu Peninsula, southwest of Tokyo, on June 17, 2017 after it had collided with the USS Fitzgerald. Japan's 3rd Regional Coast Guard Headquarters / AP

Arata Yamamoto reported from Tokyo, Courtney Kube and Phil McCausland reported from the U.S.