Greek authorities urged residents of a coastal region west of Athens to abandon their homes as a massive wildfire raged uncontrolled on Monday, closing one of Greece's busiest motorways and sending plumes of smoke over the capital.

Authorities deployed firefighters and equipment from across Greece to deal with the disaster at Kineta, a small resort town about 54km west of Athens on a route tens of thousands of drivers use daily to reach the Peloponnese.

Strong winds fanned towering walls of flames, which stretched as wide as 6 km, according to local officials. The main Athens-Corinth motorway, one of two road routes to the Peloponnese peninsula, was shut and train services disrupted.

"The fire rages unabated," said Stavros Fotiou, vice mayor of the town of Megara. "We urge residents to head towards Corinth to protect themselves and their children".

A senior fire chief went on state TV to appeal to people to leave the area. "People should leave, close up their homes and just leave. People cannot tolerate so much smoke for so many hours."

"This is an extreme situation," Achilleas Tzouvaras said.

Some householders took up hosepipes to douse the flames while police assisted with the evacuation of some areas.

Raging in the Saronicos Gulf, the blaze was visible for kilometres. An onimous, thick cloud of black-orange smoke hung over the Acropolis hill and the Parthenon temple in Athens on Monday afternoon.

Fanned by strong winds which were quickly changing direction, the blaze burned across wide areas of pine forest and television images showed gardens burning. It was thought to have started in a ravine in mountains overlooking Kineta, which is a popular resort town among Athenians.

"We have many assets out to protect residences, and primarily lives," said Yannis Kapakis, the general secretary of the Civil Protection Ministry.

Wildfires are common in Greece in summer, but a dry winter has created tinderbox conditions. Dozens of people died when fires raged for days across the Peloponnese in 2007.