Dozens of migrants have been forced off a cargo vessel by Libyan authorities after refusing to disembark over fears of abuses, in a move decried on Wednesday by human rights groups.
The 79 asylum seekers and migrants were forcibly removed on Tuesday from the Panama-flagged commercial ship Nivin after rejecting demands for 10 days to get off in the Libyan port of Misrata.
"The humanitarian community is saddened by the turn of events in Misrata," United Nations humanitarian coordinator for Libya Maria Ribeiro said in a statement.
"We regret the reports that some of the people onboard were injured during the forced disembarkation and transferred to the public hospital."
Ribeiro said humanitarian organisations had "strongly advocated for a peaceful solution" and it was "regrettable" that mediation efforts had failed to achieve this.
Human Rights Watch (HRW) on Wednesday condemned the use of force as "the worst possible conclusion to the desperate plea of the people on board the Nivin to avoid inhuman detention in Libya".
It said the Nivin had rescued the group from their sinking rubber dinghy in the waters off Libya under instructions from Italy's Maritime Rescue Coordination Committee on November 7 and then docked in Misrata.
The United Nations said that nationals from Ethiopia, Eritrea, South Sudan, Pakistan, Bangladesh and Somalia were among those onboard.
"Libyan authorities should immediately allow United Nations and nongovernmental personnel to visit the people removed from the cargo ship, find alternatives to their detention, and investigate the possible use of unlawful force," HRW said.
Plunged into chaos following the overthrow and killing of longtime dictator Muammar Gaddafi in a NATO-backed uprising in 2011, Libya has become a prime transit point for sub-Saharan African migrants making dangerous clandestine bids to reach Europe.
People smugglers have taken advantage of the turmoil, putting African migrants seeking to reach Europe at greater risk.
Many migrants, intercepted or rescued at sea, find themselves held in detention centres where they face dire conditions.
Amnesty International says migrants held in Libyan facilities "are routinely exposed to torture, rape, beatings, extortion and other abuse".
The UN warned last week that the situation in Libya's detention centres "continues to deteriorate" because of food shortages and the spread of diseases including tuberculosis.