SEOUL – South Korean authorities said on Sunday that they have seized and are investigating a Panamanian ship suspected of selling oil to North Korea in violation of United Nations sanctions.

The Koti has been detained at the South Korean port of Pyeongtaek-Dangjin since Dec. 21 and most of its crew members are Chinese and Myanmar nationals, South Korean news agency Yonhap reported citing maritime authorities.

This is the second case of a ship being investigated by South Korea for supplying crude oil on the high seas to North Korea after Seoul announced on Friday that it had seized a vessel sailing under a Hong Kong flag.

The Lighthouse Winmore was detained on arrival at Yeosu port on Nov. 24 after allegedly transferring some 600 tons of refined oil to a North Korean vessel on Oct. 19.

UN resolution 2375 unanimously approved in September following the latest and most powerful nuclear test by Pyongyang, from Oct. 1, 2017 limited the supply of crude oil to North Korea.

Pyongyang’s repeated arms tests, including the launch of ballistic missiles, led the UN to stiffen its sanctions on Dec. 22, limiting even further its access to oil products.

After the announcement that the Hong Kong vessel had been held by Seoul, US President Donald Trump lashed out at China for alleged oil sales in violation of the UN sanctions imposed on North Korea.

“Caught RED HANDED – very disappointed that China is allowing oil to go into North Korea. There will never be a friendly solution to the North Korea problem if this continues to happen!” Trump tweeted.

Beijing denied involvement in any such act.