None of the 17 missing sailors of a South Korean fishing vessel that sank near Antarctica on Monday have been found.

The 600-ton “No. 1 In Sung” sank early Monday morning due to unidentified causes. Five of the 42 crew members were found dead, while 20 have been rescued and 17 remain missing.

The South Korean government says that two Korean fishing boats will continue search operations in the area where the ship went down and that a Russian vessel is expected to join the search efforts. Three New Zealand ships suspended search operations on Tuesday, citing a minimal possibility that any of the 17 have survived.

The ministry says that harsh weather conditions are impeding the search efforts.