Survivors rescued from a deflating rubber dinghy in the central Mediterranean say about 50 people who left Libya with them a week ago died during the journey, humanitarian relief group SOS said.

The ship Ocean Viking spotted the dinghy with 25 people on board on Wednesday. Two of them were unconscious and were evacuated by the Italian army for treatment. The other 23 people are in serious condition, exhausted, dehydrated and burned by the fuel on board the boat.

Organization spokesperson said that refugees are native to Senegal, Mali and the Gambia.

The United Nations’ International Organization for Migration (IOM) says 227 people have died along the perilous central Mediterranean route this year through March 11, not counting new people reported missing and presumed dead.