Rescue teams in Greece searched Saturday for 12 people believed to be missing from a ferry that caught fire in the Ionian Sea while en route to Italy and continued burning for a second day.

After working all night to extinguish the blaze, firefighting vessels surrounded the Euroferry Olympia, which was carrying more than 290 passengers and crew members when the fire broke out onboard Friday.

The Greek coast guard and the crews of other boats evacuated some 280 people to the Greek island of Corfu. Authorities increased the number considered missing from 11 to 12 after discovering that a person from the ferry was not listed on the passenger manifest.

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“A very large rescue and firefighting effort is still underway, as is the search for the 12 people missing that include three Greeks and our thoughts with all their families,” shipping minister Giannis Plakiotakis told private Skai television.

The other missing passengers were believed to be mostly from Bulgaria. Officials said the people rescued included citizens of Albania, Turkey, Bulgaria, Romania, Greece, Italy, and Lithuania.

The fire broke out three hours after the ferry left the port of Igoumenitsa in northwest Greece for the Italian port of Brindisi. The vessel was transporting 153 trucks and 32 cars.

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The cause of the blaze was unclear. The Italy-based company that operated the ferry said the fire started in a hold where vehicles were parked.