The International Organization for Migration says the bodies of 18 migrants who likely died of dehydration have been found in the Sahara desert in northern Niger.

Giuseppe Loprete, the IOM's chief of mission in Niger, said in a statement Sunday that the migrants were believed to have died on June 3 after a sandstorm threw them off their route from the northern town of Arlit to Algeria.

Most of the dead came from West African countries, part of a wave of migrants trying to reach Libya to board smugglers' boats across the Mediterranean Sea into Europe. They included 17 men and one woman.

Loprete said the deaths highlight "a feared by hitherto little-known danger too many migrants face long before they risk their lives at sea."