Aid group MSF says detained migrant killed in Libya
The violence underscored the peril vulnerable migrants face in the conflict-torn country.
The international aid group said there were mounting tensions in recent weeks inside institutions that house refugees and migrants including women, children and unaccompanied minors.
Since the 2011 NATO-backed uprising that ousted and killed longtime dictator Muammar Gaddafi, Libya has emerged as the dominant transit point for migrants fleeing war and poverty in Africa and the Middle East.
Smugglers often pack desperate families into ill-equipped rubber boats that stall and founder on the dangerous Central Mediterranean route.
In the latest such incident, Libya's coastguard intercepted an inflatable boat carrying 138 Europe-bound migrants off the country's western coast last month, the country's navy said.
More than half of the migrants were from Sudan, while the rest were from other African countries, the navy added.
Nine women and three children were among the group, an AFP correspondent said.
They were all taken to a naval base in the capital Tripoli.
International agencies frequently denounce the return to Libya of migrants intercepted at sea, due to the chaotic situation in the country and poor conditions in detention centres.
Agencies contributed to this report.