A wildfire that spread rapidly across the Cycladic island of Paros on Tuesday is believed to have started inside the island’s landfill, in an area that is not designated for waste disposal but still had piles of tree branches and household refuse, according to preliminary findings by fire investigators.

Investigators believe a garbage truck unloaded waste at the site about an hour before the fire broke out. Fire service officials told Kathimerini they have not ruled out the possibility that the blaze began from spontaneous combustion in refuse already at the location.

Late Wednesday, authorities arrested Paros Mayor Costas Bizas, the municipality’s deputy mayor responsible for sanitation, a contractor for the South Aegean Solid Waste Management Agency (FODSA) and the driver of the garbage truck under Greece’s summary arrest procedure in connection with the landfill fire.

At the time the fire started, a municipal worker operating a bulldozer about 500 meters away reportedly had no direct line of sight to the ignition point. The first signs of smoke were spotted by a security guard at the landfill entrance, who alerted the fire service and a municipal employee.

Driven by strong winds, the blaze quickly spread southward across the island, burning mostly low vegetation and triggering a series of evacuations.