North Korean coast guard vessels inspected a Russian cargo ship in the Sea of Japan on Saturday and were escorting it to a North Korean port, Russia's maritime rescue service said.
"The cargo ship Lidia Demech loaded with cars, registered in Kamchatka, was heading from the Japanese port of Hamata to Vladivostok and was inspected near the Cape of Musudan," it said in a statement.
The reason for the ship carrying 25 crew members having been boarded and escorted to port was not immediately known.
The Russian news agency RIA-Novosti reported, citing a source in Russia's Pacific fleet, that the ship had probably straying too close to a North Korean missile testing site.
According to the Russian maritime rescue service the Lidia Demech was boarded between three and five nautical miles from the North Korean coast. Most countries claim 12 nautical miles from their coast as territorial waters.
The North Korean consulate in the nearby port of Nahodka told the ITAR-TASS news agency it had no information from Pyongyang on the reason for the ship being inspected and escorted to port.
North Korea held a Russian ship that sought shelter from a storm in 2005 for 15 days before letting it go following Russian diplomatic pressure.
