Greek firefighters struggled to control two new blazes that broke out around Athens on Monday, forcing the evacuation of several villages and clouding the sky over the capital as they braced for a long night battling the flames.

Greece's prime minister has linked the devastating fires to the "climate crisis", speaking last week as wildfires swept across the Mediterranean, engulfing parts of Greece, Italy and Spain.

Scores of firefighters battled fresh blazes near the Greek port city of Lavrio southeast of Athens, as helicopters and planes bombed the flames with water, a firefighting official told AFP.

Locals from three nearby villages were ordered to evacuate.

Authorities said that the fire had reached several houses, but the extent of the damage was unclear. The sky in Athens was once again covered in smoke.

"The fire front is large and the winds in the area are very strong," Thanasis Avgerinos, the deputy governor of East Attica region told AFP.

"This is a very flammable pine-covered area."

Firefighters are battling to keep the flames away from a national park in the Sounion area, as it will then be extremely difficult to control the blaze.

Meanwhile, another forest fire broke out in Vilia, Attica, about 60 kilometres (40 miles) northwest of Athens, prompting the mobilisation of air and ground forces.

Authorities have called for the evacuation of at least four nearby villages, while another 40 firefighters were battling the blazes, according to a firefighting official.

Scores of firefighters battled fresh blazes in Greece Monday, including near the village of Markati, near Athens
Scores of firefighters battled fresh blazes in Greece Monday, including near the village of Markati, near Athens AFP / Angelos Tzortzinis

The fires come on the heels of blazes in recent weeks that have destroyed homes, property, pine forests, wildlife and livestock across more than 1,000 square kilometres (386 square miles) of land.

The island of Evia, 200 kilometres northeast of Athens, has paid the heaviest price with more than half of the land burned.

The Peloponnese peninsula, 200 kilometres west of Athens, as well as the northern suburbs of the capital, were also heavily affected by about 600 fires.

Those blazes were finally brought under control on Friday.

Prime Minister Kyriakos Mitsotakis said the fires offered a dire warning.

"The climate crisis tells us everything must change," he said last week.

As global temperatures rise, heatwaves are predicted to become more frequent and intense, and their impacts more widespread, scientists say.

Meanwhile, Deputy Civil Protection Minister Nikos Hardalias, who has been coordinating the fire-fighting efforts, suffered an "ischaemic episode" and underwent a successful heart operation, the hospital treating him said in a statement on Monday afternoon.

The minister, 52, will remain at the cardiological clinic for monitoring, it said.

Secretary General for Civil Protection, Vassilios Papageorgiou, will step in until Hardalias recuperates, according to a statement by the Greek Civil Protection department.