The Italian coast guard said on Sunday it had launched a rescue operation to save more than 600 migrants who sent emergency calls for help after getting into difficulty between the Italian island of Lampedusa and the coast of Libya.

It said several merchant ships were helping with the operation, adding that the rescue vessels had located six boats drifting about 80 kilometers (50 miles) from the Libyan coast. Around 150 migrants on two vessels had already been saved, officials told Italy's AGI news agency.

A coast guard source said as many as 1,300 migrants in 10 boats could be in need of rescue.

The operation is the second of its kind in recent days, after some 700 migrants on board six dinghies were rescued off the Libyan coast on Friday.

Last week, more than 300 died in the Mediterranean while trying to cross to Europe from North Africa, reigniting criticism of Italy's decision last year to close its full-scale search and rescue mission, Mare Nostrum. The mission has been replaced by a European Union operation called Triton, which has fewer ships and patrols a smaller area.

Last year, more than 3,200 people died while trying to reach Italy by boat from North Africa, according to United Nations estimates.

tj/cmk (Reuters, AFP)