A firefighting vessel works to extinguish a fire onboard the Italian-flagged ferry Euroferry Olympia (left), off the Greek Ionian island of Corfu on February 19, 2022. Photo: AFP

At least 12 truck drivers remained missing from an Italian-flagged ferry ablaze for a second day off Corfu Saturday, as criticism mounted over conditions onboard. 

The blaze on the Euroferry Olympia prevented rescuers from boarding, but tugboats managed to tow the vessel closer to the island, ERT television said.

The ferry on Saturday afternoon was just some 6 nautical miles (around 11 kilometers) north of Corfu, ERT said, after anxious relatives started arriving in the morning.

A thick cloud of black smoke billowed into the sky after wind rekindled the fire, with Greek state agency ANA reporting the heat had reached 500 C.

The coastguard has said those missing were all lorry drivers - seven from Bulgaria, three from Greece, one from Turkey and one from Lithuania.

On Friday, 280 passengers were evacuated to Corfu after a blaze broke out the previous night as the Olympia was en route from Greece to Italy. 

Rescuers who boarded the burning vessel halted work Friday evening because of the intense heat, dense smoke and darkness, ANA said.

The cause of the fire remains unknown.

Shipping minister Giannis Plakiotakis said that a team from the Maritime Accident and Incident Investigation Service was in the area to launch a probe.

ERT reported the vessel's captain and two engineers had on Saturday been brought before a prosecutor.

Plakiotakis told Skai television that, after the fire is extinguished, the ferry would be towed to safety in order to pump out any fuel, and avoid marine pollution.

Italy's environment ministry said a "possible spill" was detected after a flyover by an Italian coastguard aircraft. 

The vessel was carrying an estimated 800 cubic meters of fuel and 23 tons of "corrosive dangerous goods," the ministry said.

The ferry was officially carrying 290 people, the ship's owner, Grimaldi Lines, has said.

Rescued truckers told Greece's public broadcaster some drivers had preferred to sleep in their vehicles because the cabins were overcrowded. 

According to the Kathimerini newspaper, the Greek trucker union had since June 2017 warned about conditions on the Olympia as well as another ferry belonging to Italian ferry and container operator, Grimaldi. 

Ilias Gerontidakis, the son of a missing Greek trucker, told the Proto Thema online newspaper the Olympia was "miserable from every point of view." 

"It had bed bugs, it was dirty, it had no security systems," he said as he waited in the port for news.

"It had 150 lorries inside. Normally it should have 70 to 75 cabins, but it only has 50. They force us to sleep four people in a cabin," he said. 

"My father, from what I was told, slept in the truck," he added.

Vassilis Vergis, the cousin of another missing driver, said he thought his relative too "was afraid of the cabins."

AFP