Rome, June 24 (RHC)-- Italy says a total of 4,500 refugees have been rescued from rubber dinghies in the Mediterranean with the help of humanitarian bodies before another boat tragedy happens in high seas.

An Italian coastguard spokesman said the refugees were brought to safety in about 40 rescue operations, backed by the navy and humanitarian organizations, in a single day on Thursday.  The coastguard, which coordinates rescue operations, said it had deployed several boats to the sea.  The Italian navy also said it had rescued 515 people from two boats.

Earlier in the day, around two dozen refugee boats had been spotted in the sea about 20 nautical miles from the Libyan port city of Sabratha, according to the Topaz Responder, a ship run by the Malta-based humanitarian group Migrant Offshore Aid Station (MOAS).

Italy has been on the front line of Europe's refugee crisis. More than 320,000 boat refugees reached the country from North Africa in 2014-15.  As of Wednesday, 56,328 refugees had reached Italy on boats in 2016, according to the Interior Ministry.

Nigerians, Eritreans and Gambians had been the top three refugee nationalities this year, the ministry said, and more than 125,000 are now living in Italian shelters.  Europe has been grappling with its biggest influx of refugees since World War II, as people flee conflict-ridden zones in Africa and the Middle East.