Tripoli — OVER 600 migrants intercepted at the Mediterranean Sea and returned to Libya at the beginning of the year are unaccounted for.
They are among 1 000 migrants returned to Libya during the first two weeks of January.
The 600 were reportedly taken to a facility under the control of the Ministry of Interior but the International Organisation for Migration (IOM) fears for their wellbeing.
"Those migrants are now unaccounted for," said an official.
Over 2 000 migrants remain detained in deplorable conditions, amid access challenges for humanitarian workers in Libya.
The United Nations has documented abuse, torture, disappearances and dire conditions in the detention centres.
The conflict in the capital Tripoli, which is in its tenth month, is worsening the woes of the detained migrants.
This week, IOM appealed to the international community to find an alternative safe disembarkation mechanism for migrants rescued fleeing Libya by boat.
The appeal came after 200 migrants were returned to Tripoli, hours after the city's main port was heavily shelled on Tuesday.
"Libya cannot wait," said Federico Soda, IOM Libya Chief of Mission.
"It is time for concrete action to ensure lives rescued at sea are taken to ports of safety, and to end the system of arbitrary detention."
Libya's Coast Guard intercepted or rescued and returned 1 700 migrants to Libya since the beginning of the year.
The North African country of some 6,5 million people remains the main point of departure for African migrants eager for improved economic opportunities in Europe.
This year, more than 3 000 migrants have arrived in Italy and Malta. They include some rescued by search and rescue vessels.