A North Korean vessel sank after colliding with a Chinese oil tanker on March 9, China’s Ministry of Transport said on Monday.

The 8500 ton Kum San struck the tanker near Lianyungang port in China’s northeast. The collision breached the hull of the North Korean ship and it subsequently sank. The 27 crew members were all rescued, and the Chinese vessel was not damaged in the incident.

The cause of the accident has not yet been ascertained, and no incident report has yet been filed with the International Maritime Organisation (IMO). The Kum San’s last positional broadcast was on March