The UN's International Organisation for Migration (IOM) has called on the European Union to better ensure the safety of migrants fleeing Libya.
Wednesday's appeal came a day after the port in the Libyan capital was attacked by missiles from forces loyal to Gen Khalifa Haftar, which have been besieging Tripoli for the past 10 months.
Hours later, about 200 migrants who had fled Tripoli by boat were returned to the port.
The IOM said the Mediterranean countries should share responsibility for providing safe havens to people rescued at sea.
At least 1,700 migrants have been intercepted, or rescued and returned to Libya this year.
UN officials are hoping that talks between the two main warring sides in Libya can still resume after the internationally recognised government withdrew from them on Tuesday.