Two Albanian seamen have died in an accident while attempting to bring back a stricken Italian ferry to the shores.

Eleven people had earlier died after the Norman Atlantic caught fire on Sunday off the Greek coast.

The sailors were part of an eight-man crew on board a tugboat when the cables attaching it to the stricken ferry snapped, the navy said.

"One man died on the spot when one cable broke after it got stuck in the propeller. The other died on board a few minutes ago when being assisted by a helicopter medical team," a port authority official in Vlore told Reuters.

Hundreds airlifted from stricken Italian ferry

The fire had broken out on a vehicle deck of the Norman Atlantic ferry, which carried 478 passengers and crew and more than 200 vehicles.

Italian and Albanian magistrates have ordered the Italian-flagged ferry, which was chartered by Greek ferry operator Anek Lines, to be seized to investigate the cause of the fire.

The aftermath of the rescue has been marked by confusion over the number of victims, with dozens of names on the ship's manifest unaccounted for and no clarity over whether they had drowned or were not on board in the first place.

With the ferry now fully evacuated, the Italian navy has said 427 people have been rescued, leaving the total accounted for well short of the 478 originally thought to be on board.

Some of those rescued were not on the ship's original manifest, and Italy's Transport Minister Maurizio Lupi has said that authorities are looking for a definitive list of passengers to cross-check it with survivors' names, adding that migrants may have been on board.

Source: Agencies