The Republic of Korea (ROK) on Thursday deported two Democratic People's Republic of Korea (DPRK) fishermen accused of killing 16 fellow crew members before crossing the border into the South last week, the ROK's Unification Ministry said.

The two men, both in their twenties, breached the inter-Korean maritime frontier off the east coast into the South aboard a squid-fishing boat on Saturday and ROK authorities detained them for questioning, ministry spokesman Lee Sang-min said.

The authorities concluded after their investigation that the men had fled to the South after killing 16 other men on the vessel, Lee said.

"We decided to deport them after determining that accepting them to our society could pose a threat to the lives and safety of our people and that such criminals cannot be recognized as refugees under international law," Lee told a briefing.

According to officials, it took a couple of days for the ROK's Navy to seize the DPRK men as they attempted to run away after crossing onto the ROK soil.

This marks the ROK's first deportation of DPRK citizens through Panmunjom.

(With input from Reuters)