Eight people died and 84 people were rescued after a boat sank off the coast of Libya, the Italian Coast Guard said.
The victims are believed to be migrants who were on the treacherous route to Europe from Libya.
Authorities said the boat was spotted Saturday by a patrol plane operating as part of a European anti-smuggling operation.
Proactiva Open Arms, a Spanish NGO that rescues migrants who run into difficulty trying to cross the Aegean and Mediterranean Sea, tweeted that only some of the migrants were rescued after spending hours in the water, and that dozens of people were still missing.
Earlier, the German rescue charity Sea Watch said that at least 25 migrants were feared dead when the rubber dinghy went down in the Mediterranean.
Libya is a well-known jumping-off point for migrants seeking refuge on European shores. Many from sub-Saharan Africa are fleeing war and persecution; others from impoverished nations in Africa, the Middle East and South Asia have made the treacherous journey in search of better economic opportunities.
The North African country is a hotbed for human traffickers, whose network of smuggling operations have gone widely unchecked due to Libya's lack of effective central governance.
Last year, 2,832 migrants died on the central Mediterranean route, according to the International Organization for Migration. At least 171,635 migrants entered European shores and just under 70% were Italian arrivals.