Search and rescue efforts are under way after a cargo ship carrying lumber capsizes between Japan and South Korea.

A spokesperson for the Japanese Coast Guard said four crew members were rescued on Wednesday after the 6,551-tonne “Jintian” sank off the coast of Japan’s Nagasaki. The four, all Chinese nationals, were picked up by nearby vessels.

The “Jintian’ sank nearly four hours after its crew sent a distress call late on Tuesday, according to Japan’s Kyodo news agency.

The crew said their ship had “tilted and is flooding”, the agency reported.

Japanese officials said 14 crew members on the Hong Kong-registered ship are Chinese and eight are from Myanmar.

According to South Korean officials, the ship’s captain last communicated with the coast guard of South Korea’s Jeju Island through a satellite phone at about 2:41am local time on Wednesday (17:41 GMT Tuesday), saying that crew members would abandon the ship.

The ship was completely submerged when the South Korean Coast Guard arrived at the scene, reported the Yonhap news agency.

The crews did not find anyone on the three life rafts and two lifeboats they searched.

There was no immediate word on what caused the vessel, which was carrying lumber, to capsize.

The incident happened as a cold snap hit much of Japan and South Korea, with heavy snow falling in some areas and daytime temperatures in some of the islands nearest the rescue site reaching just 3C (37F).

Japan’s coast guard said winds were strong at the time the distress signal was received.

It said it had dispatched patrol boats and aircraft to the area, but their arrivals were delayed by rough weather.