The Italian-owned Norman Atlantic ferry arrives at the port of Brindisi, Italy, on Jan. 2, 2015. Italian prosecutors recovered the black box of the burned-out Norman Atlantic ferry after inspection on Friday, after the ship docked at the port of Brindisi, local media reported. Photo: Xinhua

Italian prosecutors recovered the black box of the burned-out Norman Atlantic ferry after inspection on Friday, after the ship docked at the port of Brindisi, local media reported.

The ship caught fire off the Greek island of Corfu on Sunday, killing at least 11 people.

"We have acquired the black box and we will verify the data contained in its recordings. We have also found documents related to the ship's cargo," ANSA news agency quoted prosecutor Ettore Cardinali as saying.

The Norman Atlantic was still smoking when it entered Brindisi port in the early afternoon, after being towed by an Italian tugboat.

The towing operations began at around 4.30 p.m. Thursday from the Albanian port of Vlora across the Adriatic sea.

Inspections will continue on Saturday, but entering the inner part of the wreck is not safe yet, according to investigators.

Further searches will be carried out to verify if more victims are trapped in the wreck. The exact number of the missing remains unclear.

"A most optimistic forecasts would be 10 people missing. The total number should not exceed 15," chief prosecutor in Bari Giuseppe Volpe told local media.

However, Italian authorities will be able to give a definitive number of the missing only "when Greece has delivered a reliable boarding list", the prosecutor added.

The Italian-flagged Norman Atlantic, chartered by Greek shipping firm ANEK Lines, was sailing from western Greece to Italy when a fire broke out in one of the garages early Sunday morning.

A 36-hour-long salvage operation was carried out by Italy's navy in cooperation with Greece, in order to evacuate all passengers amid stormy seas and gale-force winds.

At least 11 people were confirmed dead and 477 people were rescued, according to Italy's coast guard. Two Albanian sailors also died on Tuesday, after being hit by a rope while trying to attach the ship in the Adriatic.

Discrepancies exist between the ferry's manifest and the names of those being rescued. Authorities believe an undetermined number of illegal migrants might be on board of the ship.

Four illegal migrants, including three Afghans and one Syrian national, are mong those being saved.

The captain of the ferry, Argilio Giacomazzi, and the Italian owner, Carlo Visentini, have been charged with shipwreck, multiple manslaughter and negligent injury.

Meanwhile, four more people, including two crew members of the Norman Atlantic and two representatives of the Greek ANEK Lines, were put under investigation.

So far, eight of the 11 victims have been identified, local media cited judiciary sources as saying. Two of them were Italian lorry drivers, whose bodies had been recognized by relatives.

First autopsies would begin on January 5th, according to the prosecutor's office in Bari.