SEOUL A South Korean fishing vessel with seven people aboard is being held by North Korea after sailing into the North's exclusive economic waters off the east coast, the South Korean coast guard said on Sunday.
Simmering tensions between the two Koreas have risen a notch in recent days with the staging of military drills by the South off the west coast, infuriating Pyongyang which threatened "physical retaliation" for the exercise.
"We have found out that our fishing vessel is being investigated by North Korean officials in the presumed North Korea exclusive economic waters in northern East Sea," the South Korean coast guard said in a statement.
"The South Korean government, according to international law, wants the swift resolution to the matter and the safe return of its vessel and its fisherman."
Yonhap news agency reported the vessel had advised the coast guard it was being taken by a North Korean patrol to a port in the communist country.
The two sides are still technically at war after their 1950-53 conflict ended in a truce, not a peace treaty.
South Korea is due to complete a five-day exercise on Monday near a tense maritime border off the west coast, the site of the sinking of one of the South's warships in March.
Tensions heightened on the peninsula following the torpedoing of the Cheonan corvette, which killed 46 sailors. The South, with the backing of Washington, blamed the North for the sinking.
North Korea has repeatedly denied any involvement.
China's Xinhua news agency said the boat carried a crew of four South Koreans and three Chinese, which may have a bearing on North Korea's response to the latest territorial spat.
China is North Korea's only major ally and host of six-party talks on North Korea's nuclear weapons program.
(Reporting by Suh Kyung-min and Jeremy Laurence; Editing by Nick Macfie)