Over 60 migrants are feared dead after a boat that departed Senegal in early July was found off the coast of Cape Verde on Monday, the International Organization for Migration (IOM) said Wednesday.

An estimated 63 people died while 38 survivors were rescued, including four children, according to IOM spokesperson Safa Msehli. The overcrowded boat left the Senegalese town of Fass Boye on July 10 with around 100 passengers.

The remains of seven people were recovered after a Spanish fishing vessel spotted the boat drifting in the Atlantic Ocean on Monday and alerted authorities. But 56 other passengers remain missing and are presumed dead, the IOM said.

Most on board were Senegalese migrants aiming to reach Europe. One survivor said the missing passengers had died during the arduous journey, according to a Senegalese official.

The tragedy highlighted the dangers of illegal migration routes used by thousands of Africans fleeing poverty each year. Smugglers often overload unseaworthy boats, leading to accidents and fatalities.

Cape Verde, located around 400 miles (640 km) off West Africa, is a frequent transit point. In January, 90 African migrants were rescued in its waters.

Senegal has seen several similar incidents in recent years. In late July, at least 16 migrants drowned when their boat sank off Dakar. Days earlier, 13 Senegalese died off Morocco’s coast.

Senegal launched a strategy to curb illegal migration through prevention, enforcement and reintegrating returned migrants. But officials said desperate citizens would likely continue risking their lives without expanded legal migration pathways.