44 migrants believed to have died after boat sank about 10 miles off Lampedusa.

An 11-year-old girl from Sierra Leone was rescued off the coast of Italy's Lampedusa island after being found at sea alone, for three days, by German NGO Compass Collective.

The crew of the rescue boat Trotamar III had been on their way to another emergency at around 03.20 on Wednesday when they heard the girl's screams for help, despite the noise of the wind and the stormy sea.

"It was a miracle to hear her voice on the high seas and with the boat's engine running" - skipper Matthias Wiedenlübbert said - "Of course, we searched for more people but after a storm that lasted for days with over 23 knots and 2.5-metre high waves, it was hopeless."

The girl was found wearing a life jacket, with two tyre tubes around her waist.

She told rescuers that she had been at sea for three days after the metal boat in which she was travelling capsized during a storm.

A search is underway for the other 44 other passengers, including the girl's bother, who are presumed dead.

The girl, who was handed over to Italian health authorities on Lampedusa at dawn on Wednesday, said the boat had departed from the Tunisian port city of Sfax.

She said that two boys who survived the shipwreck stayed alongside her in the water before being "taken away by the sea" two days earlier.

The night before she arrived at Lampedusa, 356 other migrants landed on the island, news agency ANSA reports, on board five boats including one carrying 111 passengers.

Over the last decade more than 24,300 people have disappeared or died trying to make the perilous sea crossing between north Africa and Italy and Malta, according to the International Organization for Migration.

Photo Compass Collective