By Benet Koleka TIRANA, Dec 30 (Reuters) - Two Albanian seamen were killed during an operation to salvage a multideck car ferry that caught fire off Greece's Adriatic Coast when a cable connecting their boat to the ferry snapped and hit them, an Albanian port authority official said on Tuesday. The deaths add to a toll of 10 confirmed victims of the disaster, but there was continuing uncertainty over how many might still be unaccounted for on the smoldering hulk of the Norman Atlantic. More than 400 people airlifted from the vessel in a 36-hour rescue operation by Italian and Greek helicopters. 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 had been rescued, leaving the total accounted for well short of the 478 originally thought to be on board. The two Albanian seamen killed on Tuesday were part of an eight-strong crew which had been towing the gutted ferry overnight. A cable connecting their tugboat to the wreck broke under high tension and hit the two men. "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. The Italian navy tweeted: "during towing, the cable broke and hit two Albanian civilian seamen," . Italian Prime Minister Matteo Renzi was due in Tirana on Tuesday for a visit which was planned before the incident. 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. Italy's Transport Ministry said on Monday Italy and Albania were deciding together where the vessel should be towed. Transport Minister Maurizio Lupi refused on Monday to confirm a Greek report saying 38 people were still missing, saying to do so would be premature. Some of those rescued were not on the ship's original manifest, and Lupi said Italian authorities are looking for a definitive list of passengers to cross-check it with the names of the survivors, adding illegal migrants may have been on board. (Reporting by Benet Koleka, writing by Isla Binnie; editing by Ralph Boulton)