A South Korean fishing vessel was seized by a Democratic people's Republic of Korea (DPRK) patrol boat after crossing the East Sea border Thursday morning, the South Korean government said.

According to Lee Bung-woo, a defense ministry spokesperson in Seoul, the 29-ton South Korean boat named "800 Yonan", with four crew members on board, was hauled to the port of Jangjon at 9:30 a. m. (0030 GMT).

"The satellite navigation system on the boat appears to have malfunctioned," the official said, adding that it crossed about seven miles into the DPRK's waters when it was seized around 6:30 a.m. (2130GMT).

The squid-fishing boat, departing the port of Geojin, Gangwon Province, on the eastern coast at 1:30 p.m. (0430 GMT) on Wednesday, was scheduled to return to its port Friday morning, he said.

"We are pushing for its release," the official said, adding South Korean authorities have sent a message calling on the north side to immediately return the ship "for humanitarian reasons".

Pyongyang responded to the message, saying it would further check into the incident and push for their release.

The incident marks the third time since 2005 when a South Korean fishing boat named "Hwangman" was seized by the DPRK authorities.

In December 2006, a South Korean vessel named "Woojin" was also hauled into the DPRK territory after crossing the border.

The two previous boats were released after nearly  3 and 18 days, respectively, according to media reports.

(Xinhua News Agency July 30, 2009)