The spokesman for the International Organization for Migration of the United Nations, Flavio Di Giacomo, said that nearly 500 immigrants who tried to cross the Mediterranean were returned to Libya, two days after two aid organizations lost contact with their boat. 

Giacomo warned, in a tweet Friday, that Libya was an unsafe port, and immigrants should never be returned to it, saying that according to international humanitarian law, immigrants cannot be forcibly returned to countries where they are at risk of mistreatment.

The International Organization for Migration (IOM) indicated that the boat, whose engine failed in international waters about 320 km away, drifted north of the port of Benghazi and more than 400 km from Malta or the island of Sicily in southern Italy.

The German NGO Sea-Watch denounced what it called “silence” by the Italian armed forces and coastguards about the boat, which went been missing three days ago, along with about 500 people. It said that the immigrants were illegally returned to Benghazi and would again suffer violence and mistreatment.

Meanwhile, Reuters reported that there were 485 immigrants who docked in the port of Benghazi on Friday, saying no further details were available to the IOM. 

Alarm Phone, a group that responds to distress calls from immigrant ships, said it lost contact with the boat on Wednesday morning. While the Italian Coast Guard said on Thursday that it had rescued 423 and 671 migrants in two separate operations in Italian waters, but Alarm Phone announced that they had nothing to do with the missing boat.