A navy video of the corpse-filled interior of the sunken fishing boat that capsized last month off Libya coupled with survivor testimony make plausible fears that some 800 smuggled migrants died in the shipwreck, prosecutors in Sicily said Friday.

Only 28 survivors, including one suspected smuggler and his alleged assistant, and 24 bodies were found in the Mediterranean in the rescue mission involving a container ship which was first on the scene. The suspects are being investigated for manslaughter, causing the shipwreck and aiding and abetting illegal immigration.

"The dimensions of the fishing boat, documented in the inspection of the ship, the imprecise but very high number of corpses able to be seen inside the wreck or right nearby, the convergent statements by survivors, indicate there were quite a few hundred persons, perhaps 800," the prosecutors' office said in a statement.

The prosecutors said the video of the undersea wreck's inspection will remain sealed to "protect the dignity of the deceased."

"The fishing boat was crammed in every corner, including interior, closed spaces, with migrants," they said.

The shipwreck galvanized the European Union to devise a strategy to combat the smuggling, which has brought tens of thousands of migrants to Italy after sea rescues this year alone.

On Friday, hundreds of the 2,200 migrants who were rescued in 11 separate operations coordinated by the Italian coast guard a day earlier reached land.

Prosecutors in Catania said the last of the survivors from last month's shipwreck to give testimony was a man from Bangladesh who was hospitalized for health problems he had before the capsizing.

Names and nationalities of the dead appear likely never to be known.