Spain's Marine Rescue service has announced the suspension of its search efforts to find more than 20 migrants from Morocco that are now believed to be lost at sea.

The missing men and women were part of a group endeavoring to travel from Africa to Europe in a 33-foot inflatable boat that ran out of fuel during stormy weather, Reuters reports. On Friday, the Spanish service spotted the boat drifting in the Mediterranean Sea off southern Spain and were able to rescue 28 African migrants, including a pregnant woman and eight children.

The now-ended rescue effort was initiated by claims from the rescued migrants that there were 23 others that had been swept away by the sea, a number which included babies. After deploying several vessels for three days and finding no trace of the missing, the service said it was calling off efforts.

A Red Cross volunteer explained what happened with the boat to El Pais.

"The immigrants say there were big waves, the engine cut out, and people started getting restless, and that, as fights broke out, they fell into the water," the volunteer said.

It is estimated that tens of thousands of migrants try to make the rough journey from North Africa to Europe every year.

In September of this year, according to the Telegraph, more than 650 migrants were thought to be drowned in the Mediterranean in two separate incidents. In one, up to 500 migrants from Egypt were feared to have perished after people smugglers deliberately rammed their boat. In the second incident, more than 160 African migrants were feared dead after an overloaded boat heading for Italy capsized off the coast of Libya.

In the Middle East, according to Al Jazerra, at least 70 Ethiopians have recently drowned after a boat used by smugglers to transport migrants to Yemen sank into the Red Sea.