A 500-ton North Korean merchant ship was driven out of South Korea's territorial waters on Thursday morning, the Joint Chiefs of Staff here said.

The ship crossed over the Northern Limit Line, the de facto maritime border, in the West Sea at 6:40 a.m. and continued to travel south past Baeknyeong and Daecheong islands and close to Socheong Island further south.

The Navy dispatched a frigate, patrol ships and speedboats to identify the ship, but it apparently did not bear any identifying name or flag.

A military source here said, "The Navy was able to identify a number on the steering house of the North Korean ship," but it took five hours to verify that the ship was North Korean.

The ship did respond after the Navy fired around 10 warning shots near Socheong Island. "The crew responded by saying 'the weather is bad' and they were on the way to Haeju, South Hwanghae Province," the source said.

The Navy ordered the North Korean ship out of South Korean waters, and it finally left them 11 hours after the first incursion. Military sources said they are suspicious of the ship's intent.

