The Royal Navy's flagship will today set off to join efforts to ease the migrants crisis in the Mediterranean.

HMS Bulwark is leading Britain's contribution to an operation European leaders hope will stem the loss of life of refugees fleeing the turmoil in Africa and the Middle East.

The 19,000 tonne assault ship has been in the Dardanelles for the Gallipoli centenary commemorations in Turkey.

A Ministry of Defence spokeswoman confirmed it will set off today.

Bulwark will be supported by two UK Border Force cutters and three Royal Navy Merlin helicopters with sophisticated radar designed to spot small surface vessels over long distances.

It will also provide a floating refuelling platform for the Merlins - expected to be based in either Malta or Sicily - enabling them to extend the range of their patrols.

The ship will work in tandem with the surveillance helicopters to provide day and night searches covering ranges of more than 100 miles.

Bulwark is expected to continue operations for around two months. UK Prime Minister David Cameron had stressed that no rescued migrants will be taken to the UK.

More than 1,700 people are estimated to have died attempting to cross the Mediterranean to Europe so far this year.

European leaders came under pressure to tackle the emergency after up to 800 people drowned off the coast of Libya last weekend.