At least eight people, including six Chinese nationals, died after a Hong Kong-flagged cargo ship sank in waters between South Korea and Japan amid fierce winter winds.

As many as 22 people were onboard the vessel, Jin Tian, when it sank on Wednesday morning about 160 kilometres (100 miles) southwest of Nagasaki, Japan.

Lyu Guijun, the consul general in the western Japanese city of Fukuoka, told state broadcaster CGTN that six of the eight victims were Chinese. The Japanese coast guard later confirmed the figures provided by Lu.

The crew had 14 Chinese nationals and eight people from Myanmar. Nine people are still missing and a rescue operation is underway to locate them. The other members of the crew were rescued by Japanese and South Korean coast guards along with other concerned authorities.

According to South Korean officials, the rescue efforts by coastguard vessels, aircraft and two commercial cargo ships were hampered by strong winds and waves.

The 6,551-tonne vessel was transporting timber and sank about three and a half hours after it first issued a call for help in Japan's exclusive economic zone, per The Independent.

The vessel owned by Shenzhen Shekou Shipping Transportation Company was on its way to South Korea's Incheon port.

It is still not clear what caused the vessel to sink. There were no signs of any collision with any other vessel. However, a gale warning was in effect when the captain made the distress call.

The incident occurred a day after parts of Japan were hit by winter storms. The authorities had to cancel hundreds of flights due to windy conditions. Daytime temperatures in some of Japan's islands nearest the rescue site reached around 3 degrees Celsius.

In a similar incident reported in 2020, a cargo ship with 43 crew members and 6,000 cattle on board sank off southwestern Japan after being caught in a typhoon.

Cargo ship
South Korea's coast guards are searching for crew from a cargo ship that sank off the southern island of Jeju