A wooden boat carrying up to 200 migrants has sunk just one kilometre off the Libyan coast, the coast guard said on Saturday, and most passengers were feared drowned.
The local coast guard said it had no boats of its own and had to commandeer fishing vessels in a rescue attempt after fishermen raised the alarm on Saturday morning.
The small boat crammed with between 150 and 200 migrants sank late on Friday near al-Qarbole, east of Tripoli, local coast guard official Mohammad Abdellatif told Reuters.
The Associated Press, quoting Abdel-Latif Mohammed of the Libyan coast guard, said there could be more than 250 people on the boat.
Photos taken by an Agence France-Presse showed several drowned bodies, including at least one child. No immediate death toll was released.
Local fishermen raised the alarm at dawn on Saturday morning and the coast guard managed to rescue 16 migrants who were still alive in the water, surrounded by bodies, Abdellatif said.
The boat had entirely disappeared when the coast guard arrived at the scene, just one kilometre from the beach, he said.
Migrants have been streaming out of North Africa in rickety boats in rising numbers for years. Many head for Italy, and so far in 2014, the total number reaching Italian shores has passed 100,000, the Italian government said this week.
Libya is a major departure point for this journey, and human traffickers are exploiting the political chaos and lack of security that has blighted the country since Moammar Gadhafi was toppled in an uprising in 2011.
Coast guard in crisis
The coast guard in al-Qarbole has no equipment and so is forced to borrow fishing vessels and tug boats to carry out their rescue missions, he added.
'The coast guard has no problem with searching for the missing illegal migrants, but the problem is who will receive them after finding them.' - Ayoub Qassem, Libyan navy spokesman
All of those rescued were released as there was nowhere to detain them, Abdellatif said. He said he had informed the local hospital, the ministry of health and the criminal investigations department of the accident but that all three had refused to collect the bodies.
In recent weeks, Libya has seen the worst violence since the 2011 rebellion as rival factions battle each other for influence and control of the country's wealth. Foreign embassies and agencies have evacuated their staff and the entire parliament has decamped to the country's east.
State authority has crumbled and basic services are becoming increasingly more difficult to come by.
"The coast guard has no problem with searching for the missing illegal migrants, but the problem is who will receive them after finding them," Libya's navy spokesman Ayoub Qassem said.
"They have no locations to accept them and the immigration authorities are not helpful enough to receive them on time," he said.
The Italian navy told Reuters they were not involved in the incident and had no further details.