SEOUL (Reuters) - A South Korean cargo vessel carrying about 4,000 cars bound for the Middle East was listing heavily on Sunday off the coast of the southern U.S. state of Georgia, an official of operator Hyundai Glovis said.

The U.S. Coast Guard said a pilot and 23 crew were aboard the Golden Ray when it overturned in St. Simons Sound and 20 people had been rescued.

Rescue teams were searching for four crew members believed to be inside the engine room of the vessel, the company and South Korea’s foreign ministry said.

The rescued included six South Koreans, 13 Philippines nationals and the American pilot, the foreign ministry said.

The cars on the ship represented marques such as Hyundai Motor and Kia Motors, the company official, who asked not to be identified because of the sensitivity of the matter, said on Monday.

“We are making rescue of crew members as our top priority. After that we will investigate any damage on cargo,” the official said.

The Vessel Finder website said the ship had recently called at the Port of Brunswick and was headed to Baltimore. The carrier was built in 2017 and was sailing under the flag of the Marshall Islands, according to the website.

The Golden Ray has a capacity to carry 6,933 vehicles according to the Glovis website.