The Italian navy organized the rescue of around 4,400 migrants in waters off the Libyan coast on Saturday, prompted by requests for help received from nearly two dozen boats, in one of the biggest multi-national operations so far.

Italy's coast guard said in a statement on Sunday that it had coordinated rescue efforts involving numerous vessels, including a Norwegian and an Irish ship as part of the European Union's Triton rescue mission.

Europe is struggling to cope with a record influx of refugees as people flee war in countries such as Syria.

The migrants were traveling aboard inflatable dinghies and overcrowded boats, the coast guard said.

The Mediterranean has become the world's most deadly crossing point for migrants. More than 2,300 people have died this year in attempts to reach Europe by boat, according to the International Organisation for Migration.

Many are seeking alternative routes to Western Europe.

On Saturday, thousands of rain-soaked migrants stormed across Macedonia's border as police lobbed stun grenades and beat them with batons, seeking to enforce a decree to stem their flow through the Balkans to western Europe.