The Italian coast guard responded Friday to three boats carrying more than 1,300 migrants that were "in danger" in the Mediterranean Sea off Italy’s southern coast, officials said.

Coast guard vessels were dispatched to rescue about 500 people on a smuggler's boat about 700 miles off the Calabria region, which forms the toe of the Italian boot. Coast guard crews also were rescuing 800 migrants from two boats in difficulty some 100 miles off Calabria.

The rescues come nearly two weeks after a shipwreck off the Calabrian coast killed at least 73 migrants who had departed Turkey. Another 80 were rescued, but more are missing and presumed dead.

ITALY STADIUM FILLED WITH COFFINS OF MIGRANTS AFTER SHIPWRECK KILLS DOZENS

Prosecutors are investigating whether Italian authorities failed to properly respond to the ship signaled by the European border control agency, Frontex. Instead of deploying coast guard boats for a rescue, they sent border enforcement vessels for a law enforcement operation.

Four smugglers have been arrested in the case, including one who was stopped by authorities in Austria.

ITALY SHIPWRECK: COAST GUARD SAYS DOZENS DEAD AFTER MIGRANT CRAFT CRASHES OFF COAST

Italy has strongly rejected any blame for the shipwreck and is adopting new measures to clamp down on smugglers.

Frontex said that crossings in the dangerous central Mediterranean Sea have more than doubled in the first two months of this year, with more than 12,000 irregular crossings. Last month alone, the numbers tripled from a year ago, to 7,000.

The U.N. migration agency estimates some 300 people are dead or missing and presumed dead along the perilous central Mediterranean route this year.