Dramatic images released by the Italian navy on Wednesday captured the moment when a heavily overcrowded boat overturned in a shipwreck off Libya which left at least five people dead.

The blue fishing vessel, its deck heaving with people, tipped over after the migrants rushed to one side on spotting a rescue ship — an all too frequent mistake which has led to many disasters in the Mediterranean.

The migrants, many of them men, some already wearing orange lifejackets as a precaution, were captured in rare photographs as they clung to the boat's rails or each other, or dropped like stones into the sea.

Some are seen hanging on to the starboard edge by their fingertips as the trawler rolls, while others try to balance on the rim.

Pictures taken seconds later show the churning waters around the boat peppered with people trying to get away from the vessel which, now overturned, begins to sink, with four people still perched on its upturned hull.

The navy said its Bettica patrol boat had spotted “a boat in precarious conditions off the coast of Libya with numerous migrants aboard” but the trawler overturned shortly afterwards “due to overcrowding”.

The Bettica threw life-rafts and jackets to those in the water, while another navy ship in the area sent a helicopter and rescue boats.

Survivors can be seen in the photographs wearing life-rings, some swimming towards the Bettica as the helicopter whirrs overhead. The navy said 562 people had been pulled to safety.

The migrants had sounded the alarm by calling for help using a satellite phone some 18 nautical miles off Libya.

The Bettica went on to pluck another 108 migrants from their dilapidated vessel in a second rescue operation on Wednesday.