Drones, warships and helicopters were deployed both inside and outside national waters following two tragic shipwrecks this month in which 400 Eritrean, Somali and Syrian refugees drowned.
Hi-tech radars and night-vision equipment are also being used in the operation, named Mare Nostrum (Our Sea) and aimed at preventing another disaster.
The navy has dispatched five warships to patrol the vast area and said in a statement today that it had already rescued 290 migrants near the island of Lampedusa, Italy's southernmost point.
The latest arrivals come on top of the 32,000 asylum seekers that the UN refugee agency says have landed in Italy and Malta so far this year.
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Most leave from an increasingly lawless Libya and arrive in Lampedusa, where the tiny local refugee centre is often badly overcrowded.
Border guards said today they had also seized a "mother ship" and arrested 17 crew members, who are believed to be Egyptian, following a landing in the southern Calabria region on Sunday.
Thousands have perished over the years as the crossings are often made on ageing vessels.
The refugee shipwreck on October 3 off Lampedusa was the country's worst ever, with 364 people killed after their 20-metre boat caught fire, capsized and sank within sight of the shore.
Just a few days later another heavily laden boat flipped over in rough seas off Malta, killing at least 36 of the Syrian refugees on board.
Europe's Home Affairs Commissioner Cecilia Malmstroem has suggested Frontex, which coordinates European border management, deploy a vast maritime search-and-rescue operation from Cyprus to Spain.
But experts have questioned how easy it will be to persuade EU governments to finance such an operation or agree to a European border control, particularly in recession-hit countries or where anti-immigration sentiment is on the rise.