The Greek government and residents traded recriminations over devastating wildfires on Thursday as its defence minister suggested "criminal" unregulated building had blocked escape routes.

Panos Kammenos, who had earlier been heckled by angry residents, claimed that unlicensed holiday homes in the densely-packed area around fire-ravaged Mati carried some responsibility for the heavy loss of life.

"This is a crime from the past," he told reporters during a visit to Mati which quickly turned sour.

"This coast of Athens, all these properties, the majority are without a licence, and they have occupied the coast without rules."

Furious residents had earlier shouted the minister down as he entered the village: "You let people burn. You left us at the mercy of God," said one woman who lost her home in the blaze.

Nikos Toskas the citizen protection minister, said on Thursday night that Greece had "serious indications" that the wildfire was caused by arson.

Mr Toskas said satellite image analysis and ground inspections suggested that the fire broke out in multiple places in a short time frame.