Nigerians were among survivors as hundreds were feared  on Tuesday dead both in the sea and the scorching Sahara desert as African migrants defied all odds and risks to flock to Europe in search of better life. The migrants were drowned as they braved their way through the sea to Europe while yet another bunch of migrants were said to have dropped dead in the heat of the desert for want of water.

Reuters reports that over 50 African migrants are feared dead in the Sahara desert of northern Niger on Tuesday after being abandoned by their drivers, aid workers and local officials said.

A convoy of three pick-up trucks were transporting over 70 migrants north through the Sahara Desert towards Libya — a typical route for West Africans seeking to reach Europe — when the drivers abandoned them.

Twenty-three of the migrants survived after walking to a nearby town for help, the International Organization for Migration said in a press release on Tuesday, which said the survivors came from Nigeria, Gambia, Ivory Coast and Senegal.

A local official told Reuters that of the remaining 52, at least 15 were known to have died from thirst while attempts on Monday to find the rest were unsuccessful. There was no immediate word on their nationalities.

“The migrants were abandoned about 50 miles from Siguidine,” Fatoumi Goudou, a prefect in the Bilma department of Niger, told Reuters.

It is not clear why the drivers abandoned their passengers, but rival militias and militants seeking money often stop migrant convoys and are a constant hazard for smugglers.

In a related development, Red Crescent volunteers said they recovered the bodies of 24 migrants on Tuesday that were washed up in an eastern suburb of the Libyan capital, Tripoli, as large-scale rescues were made in the Mediterranean.

Residents in Tajoura district said the bodies had begun washing up at the end of last week. Several had been partially devoured by stray dogs, according to a local coast guard official.

The toll was expected to increase as the flimsy boats used to carry migrants as far as international waters normally carry more than 100 people.

Three migrants died in the Mediterranean on Monday night, a German aid group said, during Italian-led rescue operations in which thousands more were pulled to safety.

About 5,000 migrants were picked up off the Libyan coast by emergency services, Italy’s navy, aid groups and private boats on Monday, and rescues were continuing on Tuesday, according to an Italian coastguard spokesman.

“Despite all efforts, three people died from a sinking rubber boat” and rescue boats in the area are struggling to cope, German humanitarian group Jugend Rettet said on Facebook.

Jugend Rettet (Rescuing Youth) is one of about nine aid groups patrolling seas into which people traffickers have sent more than half a million refugees and migrants on highly dangerous voyages towards Europe over the past four years.

“We reached the capacity limit of our ship, while our crew is seeing more boats on the horizon. Currently, all vessels are overloaded,” Jugend Rettet added.

The total number of migrants reaching Europe by sea so far this year is less than half that counted in the same period of 2016, thanks to a deal between the EU and Turkey which blocked a once-busy route to Greece. But the number coming to Italy has risen.

About 72,000 migrants arrived in Italy on the perilous route from Libya between Jan. 1 and June 21, roughly 20 percent more than in 2016, and more than 2,000 died on the way, according to the International Organization for Migration.