Survivors aboard a deflating rubber dinghy rescued in the central Mediterranean Sea have reported that some 50 people who departed Libya with them a week ago perished during the journey, the humanitarian rescue group SOS Mediterranee has said.

The European charity’s ship Ocean Viking spotted the dinghy with 25 people on board on Wednesday. Two were unconscious, and died. The other 23 were in a serious condition, exhausted, dehydrated and with burns from fuel on board the boat.

SOS Mediterranee spokesman Francesco Creazzo said that the survivors were all men, 12 of them minors with two of those not yet teenagers. They were from Senegal, Mali and Gambia.

Mr Creazzo said the survivors were traumatised and unable to give full accounts of what had transpired during the voyage.

Humanitarian organisations often rely on accounts of survivors when pulling together the numbers of dead and missing at sea, presumed to have died.

The UN International Organisation for Migration says 227 people have died along the perilous central Mediterranean route this year through to March 11, not counting the newly reported missing and presumed dead.

This was out of a total 279 deaths in the Mediterranean since January 1. A total of 19,562 people arrived in Italy using that route in the period.

The survivors said the boat departed Zawiya, Libya with 75 people on board, including some women and at least one small child. The motor broke sometime after departure, and they had been adrift.