A Belgian sailing yacht in the Black Sea has picked up the two sole survivors from a North Korean-registered cargo ship, the Tolstoy, which sank after it split in two in rough waters off the Bulgarian coast on Saturday.

The yacht Mirage was en route from Tsarevo to Istanbul when they came across a liferaft containing the two Ukrainian seamen, Andrey Krizhenovski and Denis Ahrameev. Nikolay Apostolov, executive director of the Executive Maritime Administration Agency said that the yacht had apparently contacted Turkish authorities by telephone as they didn’t have a radio on board.

The two Ukrainian seamen sent a text message from their life raft to a family member late on Saturday but despite searching all day Sunday, Bulgarian rescuers failed to find them.

No word has been heard of any other surviving crew of the complement of nine, in spite of seven Bulgarian ships and a helicopter searching the area where the ship sank.