South Korea asks North to free vessel and crew

South Korea asked North Korea to quickly release a fishing boat and its four crew members, hours after the vessel was seized after accidentally crossing the countries’ maritime border, an official said today.

The incident added to tensions between the countries over the North’s nuclear and missile programs, and to the steady deterioration in ties since early last year.

Seoul’s Unification Ministry made the formal written request to North Korean authorities, ministry spokeswoman Lee Jong-joo said. The ministry is responsible for handling relations with the North.

North Korea confirmed that it had received the request and told South Korea by telephone that it would look into the matter, Lee said. North Korea’s state news agency, monitored in Seoul, did not mention the incident.

The seizure took place early this morning when a North Korean patrol boat took the 29-ton vessel 800 Yeonan into custody after it crossed into the North’s waters, apparently because its satellite navigation system malfunctioned, an official at South Korea’s Joint Chiefs of Staff said.

The official, who spoke on condition of anonymity, said the boat’s whereabouts were unknown and it was unclear whether it had been towed into a North Korean port.

Relations between the Koreas worsened last year after a conservative pro-U.S. government took office in Seoul, advocating a tougher policy on the North. In retaliation, Pyongyang cut ties and halted all major projects except a joint industrial complex just across the border in North Korea.