The Alarm Phone group announced that it had lost contact with 70 illegal immigrants who were heading for Europe across the Mediterranean from Libya.

The migrants had been missing for four days after leaving the port of Khoms, some 120 kilometers west of the capital Tripoli. "They departed from Khoms, Libya, & called Alarm Phone several times," the group tweeted.

The non-governmental group that runs a hotline for migrants in distress at sea confirmed that it lost contact with the migrants in the Malta search and rescue zone, some 11 miles to Italian waters, but there is no record of their rescue or arrival.

It demanded the concerned authorities provide information on the migrants' fate. "How can 70 people vanish at sea, a few miles from land? What happened to them? Why did Maltese and Italian authorities refuse first to rescue them." the Alarm Phone tweeted.