Italy has called for an emergency summit of European Union leaders following the latest migrant boat tragedy in the Mediterranean.

Prime Minister Matteo Renzi said Rome would be seeking the extraordinary meeting after up to 700 people were feared to have drowned when a boat carrying them towards Italy capsized off Libya.

Mr Renzi said: "We are working to ensure this meeting can be held by the end of the week, it has to be a priority." 

He described the people smuggling behind the migrant crisis as "scourge" that Europe had to address.

The Italian initiative came as the EU came under fire over what NGOs termed a tragedy that may have been avoided if Italy had maintained its large-scale search-and-rescue operation off its southern shores.

The Mare Nostrum mission was suspended at the end of last year after Italy's EU partners refused to help with the ongoing cost of running it.

There was a bitter row over whether the life-saving operation was unintentionally encouraging migrants and asylum-seekers to attempt the perilous crossing from north Africa to Europe.

In a statement, the European Commission said: "For as long as there is war and hardship in our neighbourhood near and far, people will continue to seek a safe haven on European shores.

The EU is considering sending warships to the Libyan coast to combat oil and arms smugglers.

But the EU fears that this move could encourage migrants to take to sea in the hope of being rescued.

These proposals were set out in a document seen by Reuters.
A naval mission is one of several options suggested by EU officials working for foreign policy chief Federica Mogherini.

The paper assesses how a proposed national unity government if UN-brokered talks between Libya's warring groups succeed. 

Another option suggested in the paper is that EU soldiers could secure oil installations in Libya to let international oil firms resume operations.

That proposed move could prevent Libyan factions obtaining arms funded by oil shipments from installations under the control of militias.