South Korea’s Foreign Ministry says it has obtained evidence that shows a Chinese fishing vessel that sank in the Yellow Sea on Saturday did so after having rammed into a ship belonging to the South Korean Coast Guard.

The ministry says three Chinese fishermen confirmed that the 63-ton boat slammed into the Coast Guard’s vessel.

South Korea says the Coast Guard’s vessel was rammed in an attempt to keep it from pursuing another Chinese fishing boat that had been fishing in South Korean waters.

South Korea says that about 50 Chinese boats were illegally fishing in South Korean waters some 120 kilometers northwest of Gunsan city last Saturday when the Coast Guard approached them. The boats then reportedly fled to neutral waters.

One of the sailors on the fishing boat that sank died and one is missing.