BRINDISI, Italy (AFP) - Italian sailors took control on Friday of a merchant ship that had been abandoned by its crew and left to power towards the country's jagged coast with 450 migrants aboard.

While sailors boarded the Ezadeen and set up a tow some 40km off southern Italy, another crew brought the burned-out ferry Norman Atlantic into the Italian port of Brindisi, six days after a fire killed 13 passengers and forced the rescue of 477.

Italian prosecutors fear that the ferry could contain the bodies of still undiscovered illegal immigrants and unregistered passengers, potentially raising the death toll far higher.

In the Ezadeen drama, six coast guard officers were lowered from a helicopter onto the deck of the Sierra Leone-registered merchant ship as it approached Crotone, off the heel of Italy, the navy said.

Once under control, the Italian coast guard began towing the 73m-long livestock vessel towards the Italian port of Corigliano Calabro, where it was expected to arrive late on Friday or early Saturday, the navy said.

The ship had been en route from Famagusta in northern Turkish-controlled Cyprus to the southern French port of Sete, according to a shipping website.

The same site also noted, however, that the Ezadeen had begun its voyage in October from the Syrian port of Tartus.

Thousands of refugees who made it to Italy this year fled war-torn Syria, though most came via North Africa.

Before it came to a halt, the nearly 50-year-old Ezadeen had been moving at a brisk seven knots, and was spotted by a coast guard plane 120km offshore shortly after nightfall.

A woman refugee on board was able to operate the ship's radio and told the coast guard that the crew had jumped ship, Italian navy spokesman Filippo Marini said.

"We are alone, there is no one, help us!" the woman was quoted as crying.

The coast guard asked for assistance from Icelandic patrol boat Tyr, which was in the area on a mission with Frontex, the European Union's border agency.

The Tyr was able to draw alongside the ship, but its speed and rough weather conditions made boarding impossible.

Once the Ezadeen had run out of fuel, five Tyr crew members were winched on to the merchant ship by helicopter to care for passengers until Italian coast guard officers arrived to take control.

"The migrants aboard were visibly distressed but overall in good medical condition. They have been provided with food, water and basic medical assistance," a Forex statement said on Friday.

SERIES OF DRAMAS

The incident marked the third in a series of dramas Italy has dealt with in several days.

The first came with the deadly fire that broke out on the Norman Atlantic ferry Sunday between Greece and Italy.

Bari prosecutor Giuseppe Volpe said almost 500 people may have been aboard - far above the 474 officially on the manifest, and prompting fears the current death toll of 13 may rise once the ferry is fully searched in Brindisi.

Mr Volpe said it had been "established" that illegal immigrants were aboard, something confirmed by several of the rescued passengers.

The search is expected to concentrate on trucks parked in the car deck where the fire started.

Italy, which is struggling with a record wave of migrants making the dangerous journey across the Mediterranean, faced yet more drama on Wednesday after the navy stopped a first crewless "ghost" ship with hundreds of migrants on board.

In that case, the Blue Sky M freighter carried nearly 770 migrants drifting towards the rocks off Italy's south-eastern shore.

The ship was on autopilot, after having been abandoned by the people smugglers, who had sailed in from Turkey via Greek waters.

The Moldovan-registered Blue Sky M got to within 8km - or 45 minutes' sailing time - of running aground before six navy officers were lowered on to the ship by helicopter, and succeeded in bringing it under control.

The vessel's passengers included some 60 children and two pregnant women, one of whom gave birth on board as the boat neared catastrophe, according to the Italian Red Cross.

Many of the migrants on the ship were treated for hypothermia or injuries, including broken limbs.

More than 170,000 people have been rescued at sea by Italy in the last 14 months, and hundreds, possibly thousands, have perished trying to make the crossing.

The migrants are almost invariably under the control of ruthless traffickers who earn thousands of dollars for every person they put to sea from Libya and other departure points in North Africa.

Increasingly, the traffickers appear to be abandoning their boats - and human cargo - once at sea for Europe, with more now using bigger vessels than the converted fishing boats and other craft they previously favoured.

The International Organisation for Migration estimated on Friday in Geneva that people smugglers grossed over US$1 million (S$1.3 million) on just one of the two abandoned ships rescued off Italy alone.