Italian navy officials say they have recovered 217 bodies from the hull of a migrant ship that sank off Libya last year in a tragedy that sparked the EU to beef up Mediterranean rescue operations.

Italian authorities raised the ship from the seabed last week and have been working to remove and identify the bodies ever since. In a statement Thursday, the navy said 52 autopsies had been performed on the 217 bodies pulled out so far.

Some of the 28 survivors of the April 18, 2015 wreck had said as many as 700-800 people were aboard, leading officials to label it one of the worst known tragedies of the Mediterranean migrant crisis.

Around 200 bodies were initially recovered; after officials saw the ship's dimensions, they suggested about 300 remained.