A senior Vatican official on Saturday deplored indifference with regard to migrants after 73 Eritreans were reported to have died from hunger and thirst trying to reach Europe from North Africa.

"Our so-called civilised societies have in reality developed an attitude of rejection of foreigners, resulting not only from ignorance but selfishness and refusal to share what one has with others," Archbishop Antonio Maria Veglio told Radio Vatican.

Veglio said that the Pontifical Council for Migrants and Itinerant People which he heads was troubled by the "ceaseless repetition of such tragedies".

"Every migrant is a human person, who as such possesses fundamental and inalienable rights which must be respected by everyone and in every circumstance," he said, quoting a recent encyclical by Pope Benedict XVI.

Five migrants rescued on Thursday off Italy's southern Lampedusa island said 73 of their companions had perished during the voyage and their bodies were dumped at sea.

The emaciated survivors said their small 12-metre (40-foot) boat -- which set off from Libya -- had been adrift without fuel for 20 days, and that they received no help from several passing vessels.

But Malta's Foreign Minister Tonio Borg said it was "extremely unfair" to criticise or blame Malta or Italy for any deaths.

Speaking at a joint news conference with the head of the Maltese Armed Forces Brigadier Carmel Vassallo and Home Affairs Minister Carmelo Mifsud Bonnici, Borg said that when the boat was first spotted, it was still in Libya's search and rescue area.

Had there been any deaths, these must have taken place in Libya's area, he said.

The Maltese authorities were also continuing to cast doubt on the migrants' story.

Vassallo said the boat carrying the five Eritreans was so small it was "highly unlikely" that it carried many more people.

Vassallo said the boat was first spotted by a helicopter from the European Union border agency Frontex when it was still in the Libyan search and rescue zone.

A Maltese patrol boat was sent to investigate and approached the migrants, who immediately insisted they did not want to stop in Malta but wanted to continue their voyage to Italy. They also informed the Maltese soldiers that 73 of their compatriots had died during the voyage and accepted some crackers, water and fuel.

He said the boat looked new, was clean and was so small that not many more would have been able to fit in it. He did not exclude that they could have been transferred to the boat during the journey.

Vassallo said the Maltese continued to monitor the boat from a distance until it was close to Lampedusa. The Italian authorities had already been informed about the migrants by then.