Bodies of African immigrants have been found washed up on shores 30 miles east of Tripoli.
It comes after nearly 200 migrants were feared to have drowned after a boat sank less than a mile from the coast of Libya during an attempted crossing to mainland Europe.
The small vessel - which was crammed with men, women and children - sank late on Friday, according to the local coast guard.
It comes as Italy's maritime search and rescue team are being called upon to retrieve hundreds of migrants who are trying to flee North Africa via the Mediterranean Sea on a daily basis.
A Libyan coastguard spokesman Abdellatif Mohammed Ibrahim said: 'A few miles off the coast, we found the remains of a wooden boat which had some 200 migrants on board.
'We managed to save 16 people and recovered 15 bodies, but the search continues for some 170 people who disappeared at sea.'
He added: 'It seems that among them are Somalis and Eritreans in addition to other nationalities. One of the fatalities was an 18-month-old child.'
Around 3,500 migrants and 19 corpses have been discovered since Friday during a spate of attempted journeys by traffickers trying to take advantage of calmer summer seas.
The Italian ship Sirio recovered 18 corpses and 73 survivors from a raft, after a frigate picked up one corpse along with 1372 survivors on Friday night.
The Mare Nostrum search and rescue mission began after a shipwreck near Italy's coast killed 366 people last October.
