SEOUL, June 16 (UPI) -- North and South Korea are increasing the number of patrol boats at a disputed maritime border, heightening tensions.
Pyongyang had already dispatched a total of five patrol boats near the Northern Limit Line, South Korean news network MBN reported Thursday.
North Korea recently added another boat, most likely to protect fishing rights during crab season, a South Korean military official said.
The presence of patrol boats has increased with the number of North Korean fishing boats. North Korean fishermen may be stepping up activity in response to an ordinance from Kim Jong Un to raise productivity, South Korean news service News 1 reported.
Pyongyang is also monitoring the South from Ari Island, located less than eight miles from the South Korean island of Yeonpyeong, which was shelled in 2010.
A South Korean military official said Seoul has confirmed the installation of radar on the island, according to News 1.
The official also said about 200 North Korean fishing boats are active near the NLL, a near doubling of the number of boats from 2015.
"As the number of fishing boats have grown, North Korea patrolling has become more vigorous," the official said.
Some of the patrol boats were being deployed to chase away Chinese fishing boats, according to local South Korea press.
North Korea has also built a base to accommodate about 70 hovercraft, less than 40 miles away from the NLL, MBN reported.
Chinese boats that were fishing illegally in South Korean and neutral waters around the NLL have moved out since the United Nations Command in the South took joint action, according to Seoul.