The Italian navy has said a large wooden fishing boat overcrowded with migrants capsized off the coast of Libya this afternoon, with 550 people rescued and five found dead so far.
Photographs show the blue fishing boat rocking violently before capsizing, sending migrants tumbling into the sea.
Hundreds rescued after boat flips in Mediterranean https://t.co/ggBzH7FckEhttps://t.co/B2jSpcHFP6
— RTÉ News (@rtenews) May 25, 2016
Some then climbed onto the hull of the overturned vessel, while others swam for life boats or toward the navy ship.
Navy swimmers are also shown pulling migrants in lifebelts toward the navy patrol boat, according to the navy pictures.
Women wearing head scarves and children were among those rescued, but no details of the migrants' nationalities have been given.
Bettica, the Italian navy boat, saw that the vessel was in difficulty and approached it to hand out life jackets, but before it could begin a rescue the boat flipped over due to the sudden movement of the passengers, a statement said.
Several rubber motor boats are being used in the rescue operations, and the navy frigate Bergamini has deployed a helicopter.
Boat arrivals rose sharply this week amid warm weather and calm seas.
Italy's coastguard said 5,600 migrants were rescued on Monday and Tuesday, and officials fear numbers will increase as conditions continue to improve.
In the past two years, more than 320,000 boat migrants have arrived on Italian shores and an estimated 7,000 died in the Mediterranean as they sought to reach Europe, according to the International Organization for Migration.
Humanitarian organisations say the sea route between Libya and Italy is now the main route for asylum seekers heading for Europe, after a European Union deal on migrants with Turkey dramatically slowed the flow of people reaching Greece.
Irish naval vessel LÉ Róisín was among the vessels involved in the rescue operations and on Monday rescued almost 400 people from the waters off Libya.
Merkel brushes off concerns over migrant deal
Meanwhile, German Chancellor Angela Merkel has brushed off concerns about the landmark deal with Turkey following critical comments by her Turkish counterpart.
Speaking to reporters, Ms Merkel said she was not worried, before adding "maybe some issues will require more time, but in principle we, for our part, will stick to the agreement."
Turkish President Recep Tayyip Erdogan has warned the EU his parliament would block laws related to the deal if they were not granted visa-free travel.
The stark warning came amid spiralling tensions between the Turkish leader and the EU over a string of issues ranging from existing accords to human rights.
There have been growing indications Turks will not be given the visa-free travel by the target of the end of June, and Ms Merkel warned after talks with Mr Erdogan that the target was unlikely to be met.
EU leaders are insisting that Turkey abide by 72 conditions before the visa exemption takes place, with a demand to change counter-terrorism laws proving particularly contentious.
The EU wants Turkey to narrow its definition of terror to stop prosecuting academics and journalists for publishing "terror propaganda".
