About 130 were treated for hypothermia and dehydration. A dozen pregnant women were taken to a nearby hospital for check-ups. One was reported to have given birth on board the ship.
Mystery surrounds exactly where the ship had come from, where it was heading and what happened to its crew, amid speculation that the vessel was part of a sophisticated people-trafficking operation. One man, a Moldovan, was arrested at Gallipoli on suspicion of being a trafficker after trying to conceal himself among the migrants.
The rest of the smugglers are believed to have fled the ship in inflatables before the Italian rescue services arrived, knowing that their human cargo would be picked up.
The drama began on Wednesday, as the ship sailed past Corfu, when somebody on board called the Greek authorities to say that the vessel was in distress and that armed men were on board. Greece sent a frigate, a helicopter and two patrol boats to check on the ship but they appear to have performed a perfunctory inspection, reporting that it had no engine problems and there was "nothing suspicious" on board. They did not board the vessel. The frigate escorted the ship until it reached international waters.
In Italy, there were suspicions that the Greeks had deliberately turned a blind eye to the emergency in the hope that it would become Italy's responsibility.
As the Blue Sky M approached the Italian coast a few hours later, Rome was compelled to send two helicopters to conduct a more thorough check.
Six coastguard officers were winched on to the deck of the Moldovan-flagged ship, which was by then just three nautical miles off the port of Santa Maria di Leuca, on Puglia's southernmost tip. They found no crew on board and the ship locked on to automatic pilot mode with the steering set for the coast.
Officers managed to unlock the engines and bring the ship under control.
Mimma Antonagi, a Red Cross spokesman, said: "The ship was abandoned by its crew in open water. If [the Italian coastguards] had not gone on board, it would have crashed into the coast."
The migrants were reportedly charged up to US$5500 ($7055) each for the passage from Turkey - about three times as much as paid by refugees trying to reach Italy from the Libyan coast.
A record 170,000 migrants reached Italy by boat this year, with more than 3000 dying at sea from drowning, after their boats capsized, or by asphyxiation in crowded holds.
Ferry search thwarted
Up to 100 people are still feared missing from a ferry that caught fire in the Adriatic as stormy weather prevented Italian authorities from towing the ship to Brindisi yesterday.
The uncertainty about the number of victims was caused by confusion over whether some passengers were not recorded on official lists and suspicions that illegal immigrants were on board the Norman Atlantic.
At least 11 people died after fire swept through the car ferry as it travelled from Greece to Italy. During a 34-hour operation, hundreds of passengers and crew were rescued, but 98 are still thought to be missing.
It is not known whether they died in the fire, which left the ferry a smouldering wreck, whether they died at sea or whether they had never boarded the vessel in the first place.
-Telegraph Group Ltd
