Updated

South Korea said Saturday that it has confirmed the safety of crew members from a fishing vessel that had lost contact in waters off Somalia, prompting Seoul to dispatch a naval unit over fears that the vessel had been hijacked by pirates.

Seoul's Foreign Ministry said it planned to "close the case" after the vessel's South Korean captain confirmed the safety of his crew in a telephone call with a South Korean business partner. While officials were still gathering details on what happened, they were sure that the vessel wasn't hijacked, according to a ministry official, who didn't want to be named, citing office rules.

Hours earlier, South Korea's military said it dispatched its anti-piracy Cheonghae Unit to the area after the 234-ton vessel, which had a crew of three South Koreans and 18 Indonesians catching squid, lost contact after relaying it was being followed by a suspected pirate vessel. Upon Seoul's request, patrol aircraft from India, Germany and Japan also searched the area, and South Korean President Moon Jae-in ordered related government agencies and the military to "invest full efforts into the rescue operation, so that not a single life is lost," according to his office.

The fishing vessel was registered in Mongolia and owned by an ethnic Korean businessman living in South Africa. The vessel's captain, chief engineer and boatswain were South Korean nationals, the Foreign Ministry said.

Crews from South Korean fishing vessels and cargo ships have often been targets of Somali pirates.

Recent weeks have seen a resurgence of piracy off Somalia's coast after five years of inactivity. The piracy was once a serious threat to the global shipping industry but lessened in recent years after an international effort to patrol off the coast.

Some Somali fishermen, including former pirates, say foreign ships illegally fishing in local waters are forcing them to return to piracy to make money.