Five bodies have been found off Malta so far as rescuers continue with their search following one of the worst disasters involving would-be illegal immigrants in the Mediterranean.

A Maltese patrol boat and two German helicopters are continuing their search in an area between 50 and 40 nautical miles south of Malta.

Eight survivors from a half-sunken dinghy told the Maltese authorities that the boat on which they were trying to reach Europe had set off from Libya with 79 people aboard. After their engine stopped, they spent the next days adrift in heavy seas as their numbers gradually dwindled.

The Malta office of the United Nations High Commissioner for Refugees (UNHCR) said Friday it had received no communication from the government, following its request for the release from detention of the eight survivors.

According to the survivors, three pregnant women were among those who were swept away and remain missing.

The UNHCR has long been calling for a review of Malta's detention policy, especially with regard to vulnerable people.

UNHCR head in Malta Neil Falzon told Deutsche Presse Agentur dpa: "We are especially calling for the release of the 15-year-old boy who is being held at Hal Far (detention centre). He should not have been put in detention in the first place. He can hardly talk and stand."