A British official says as many as half a million people in Libya are looking to cross the Mediterranean's perilous waters this summer to Europe in search of a better life.
Captain Nick Cooke-Priest said aboard the British warship HMS Bulwark, there are indications that as many as "450,000 to 500,000 migrants in Libya are waiting at the border" for the voyage across the Mediterranean.
On Sunday, Britain's Ministry of Defense said the Bulwark had been dispatched to rescue at least 500 migrants after a helicopter had identified four migrant vessels in distress.
Also Sunday, an Italian coast guard ship carrying 316 migrants from three separate operations off Libya's coast docked at Lampedusa.
This all follows rescues on Saturday when naval vessels from Italy, Britain, Ireland and other countries rescued nearly 3,500 migrants off of Libya's coast.
There has been a recent spike in migrants making the risky trip across the sea. Observers say worsening conditions in lawless Libya, the North African staging place for many migrant journeys, are to blame. Many of the migrants come from Syria, Nigeria, Mali and Eritrea, fleeing war, political persecution and economic woes.
Italy has sought relief from sheltering the migrants, asking other European Union members for help. The EU has pressed its members to share the responsibility, but some members are opposed to taking in the migrants.
According to the International Organization for Migration, more than 80,000 people have crossed the Mediterranean this year. More than 1,800 migrants have perished at sea or remain unaccounted for.
Some information for this report came from AP, AFP and Reuters.