North Korea has threatened to take stern measures if South Korea does not repatriate five North Korean sailors that South Korean Coast Guard rescued on Saturday in waters near Ulleung Island in the East Sea.

In a message addressed to the head of the South Korean Red Cross on Wednesday, the North Korean Red Cross chief called for the immediate return of the five, including the three fishermen who expressed their intentions to defect to South Korea. 

Pyongyang in the message claimed that forcing the rescued to defect from the North is an anti-humanitarian crime. It then threatened to take stern measures in the event all five are not returned home. 

Seoul's Unification Ministry said on Saturday that the South Korean coastguard rescued a North Korean vessel and its five crew. The ministry said three of the five expressed their desire to defect from the communist home country.