One worker died and another was seriously hurt Friday in an accident at one of Greece's biggest refineries near Athens, the company said.

The Motor Oil refinery said both men were external contractors, but did not give details on the accident.

Greek media attributed the accident to an explosion and said three other workers were lightly injured at the facility in Agioi Theodoroi near Corinth, around 70 kilometers (45 miles) west of Athens.

The company said that one worker had died and that the second was in "critical" condition.

Motor Oil said it was "fully cooperating" with an official investigation. But police detained a site supervisor over the incident, state news agency ANA said.

Motor Oil had earlier said the accident occurred "during extensive preventive maintenance" at the refinery which suffered its second deadly accident in six years.

In 2020, one man died and three others were injured in an explosion at a refinery medical room.

Three maintenance workers died there in 2002 after inhaling poisonous fumes in a fuel tank.

Four people were injured in a 2024 fire at the refinery, which is owned by the Vardinogiannis group, controlled by one of the country's most influential families.

© Agence France-Presse