At least 143 refugees are feared dead after a Europe-bound boat capsized off the coast of Mauritania, according to the United Nations refugee agency (UNHCR). In a statement on Tuesday, the agency expressed deep sorrow over the incident. The boat had departed from Bafouloto in Gambia and drifted at sea for 25 days before being rescued on July 18. When it reached the port of Nouadhibou, 38 survivors and several bodies were found on board.

UNHCR spokesperson Matt Saltmarsh told reporters in Geneva that two children among the survivors had lost all their family members during the journey and were receiving hospital treatment. The agency also reported that another person died after disembarking from a separate vessel that arrived in Mauritania on July 14. All the victims were citizens of various African countries.

Mauritania’s coast guard said the boat carried 160 passengers and that the accident occurred after it ran out of fuel. UNHCR described the Atlantic route to the Canary Islands as one of the world’s deadliest migration paths and urged expanded education and employment opportunities to reduce such perilous journeys.