The Royal Navy rescued more than 1,000 people off the coast of Libya today, making it HMS Bulwark's "largest operation to date".

Using both its water and air capability, the 19,000-tonne assault ship conducted five different rescue missions, with a further two ongoing.

Helicopters were deployed and successfully spotted a number of migrant vessels - often in poor visibility - allowing boats from HMS Bulwark to get to them.

The latest callout saw the use of all eight of the warship's landing craft and among the migrants rescued were at least 10 pregnant women.

Nick Cooke-Priest, Captain of HMS Bulwark said: "Starting very early this morning, this has been an intense, complex day. My helicopters have done a brilliant job locating a number of migrant vessels and my landing craft have effected their rescues with typical professionalism and complete success."

He added: "In many ways this search and rescue mission is like an amphibious operation - I've deployed landing craft and aircraft in multiple waves, in poor visibility, operating autonomously over the horizon - the objective this time, of course, being to save life."

"But it's only through being trained for high-intensity warfighting operations that we are able to execute such activities in peacetime."

HMS Bulwark and three Royal Navy Merlin Helicopters deployed to the Mediterranean on May 5 have played a leading role in the EU's mission to stem the flow of illegal migrants into the continent.

The latest rescue brings the total number of individuals saved by HMS Bulwark so far to more than 2,700, with it plucking 747 people from dangerously overcrowded boats in a similar operation last week.

The warship was sent by the Government on May 4 to help search and rescue efforts in the Mediterranean in a bid to tackle a dramatic increase in the number of people dying trying to cross the sea.

It is estimated that more than 1,600 people have drowned so far this year trying to make the crossing.

Many are fleeing war in Libya, where Islamic State fighters are terrorising the population, fuelling instability in the war-torn country.

Defence Secretary Michael Fallon thanked HMS Bulwark for its "unwavering efforts" at sea, but said that it was necessary to look at the root cause of the problem, rather than just addressing the symptoms.

This was reiterated by Prime Minister David Cameron as he arrived at the G7 summit in Garmisch-Partenkirchen, Germany.

He said that Britain is a country that "doesn't walk on by" and that the flagship had been deployed because the UK is a "country with a conscience".

But he warned that the causes of the mass exodus from Libya must be dealt with, not just the consequences, adding: "But we also need to do more to stop these people leaving their countries in the first place.

"That's what we are using our aid budget for, that's why we will be talking here at the G7 about how we try and put a Libyan government together.

"We need to deal with the causes of this migration, not simply with its consequences."

Mr Cameron pledged the ship on April 23 ahead of an emergency EU summit to discuss how European countries could cooperate on the issue.

HMS Bulwark, a landing platform dock, is designed to put ashore Royal Marine commandos in assaults by sea, by boats launched from the dock compartment, and from two helicopters from the deck.

It has a nautical range of 8,000 miles and can carry up to 700 troops on top of a crew of 325.