A South Korean fishing boat has been seized by North Korea after crossing the inter-Korean maritime border in the East Sea.

According to a military official in Seoul, the "800 Yeonan-ho" crossed the Northern Limit Line around 6:30 a.m., Thursday. The official said the South Korean military spotted the vessel being towed by a North Korean patrol boat toward the North’s Jangjeon Port.

The official said that the 29-ton vessel is believed to have strayed into North Korean waters due to a malfunction in its global positioning system and that it was not seized in South Korean waters.

The official said the boat, which departed from Jejin Port late Wednesday, was fishing for squid in waters some 43 kilometers from the eastern port before sailing off course into North Korean waters.

A South Korean naval vessel urged North Korean officials over the radio to immediately return the fishing boat, but the North did not respond.