Residents fled their homes on Sunday as a fast-moving wildfire outside Athens fuelled by hot, windy weather burned trees, houses and cars and sent smoke clouds over the Greek capital.

More than 400 firefighters backed by 16 waterbombing planes and 13 helicopters battled the blaze that broke out at 3 p.m. (midday GMT) and quickly reached the village of Varnavas 35 km (20 miles) north of Athens.

As night fell, firefighting aircraft ceased operations until morning. Flames turned the sky orange.

"The situation remains dangerous as the fire is spreading between residences," fire brigade spokesperson Vassilis Vathrakogiannis said.

He said the blaze spread fast, "like lightning", due to gale force winds. Flames as high as 25 metres swallowed up trees and shrubland.

Varnavas is a sparely populated area with about 1,800 residents, according to the latest census.

"The village was surrounded in no time, in no time. It's really windy," resident Katerina Fylaktou told Reuters. "It started from one point and suddenly the whole village was surrounded," she said.

Hundreds of wildfires have broken out across Greece since May and scientists attribute their frequency and intensity to the increasingly hot and dry weather conditions linked to climate change.

After its warmest winter on record and long periods of little or no rainfall, Greece also registered its hottest June and July and is forecast to record its hottest-ever summer.

"We are expecting a very difficult week," said Kostas Lagouvardos, research director of the Athens Observatory. "If the Varnavas blaze is not contained during the night, we will have a problem tomorrow," he said.

Fires have also burned this summer amid extreme heat elsewhere in Europe, including in Spain and the Balkans.