By Angeliki Koutantou and Stamos Prousalis

DERVENOCHORIA, Greece (Reuters) -A wildfire swept uncontrolled through forests north of Athens for a second day on Tuesday after intensifying overnight, and authorities told residents of nearby villages to leave their houses as flames approached.

The blaze raged in the area of Dervenochoria about 30 km (18.6 miles) north of Athens. An alert through the pan-European Union 112 emergency phone number urged villagers to evacuate, Ioannis Artopoios, a Greek Fire Service spokesman said in a televised briefing.

Fire fighters managed to contain other blazes southeast and west of the Greek capital but the fronts were still active.

"Civil protection forces gave an all-night fight," he said, adding that about 250 firefighters assisted by 75 fire engines, 11 aircraft and nine helicopters battled the fire in Dervenochoria.

France and Italy will send four Canadair water bombers upon Greece's request for assistance, EU Crisis Management Commissioner Janez Lenarcic tweeted on Tuesday.

Prime Minister Kyriakos Mitsotakis is cutting short his trip to Brussels for an EU-Latin America summit due to the ongoing fires, a government official said.

Another fire weakened on Tuesday, having first broken out on Monday in the village of Kouvaras, about 27 kilometres southeast of the Greek capital. Fanned by shifting winds, that fire had quickly spread to the coastal towns of Anavyssos, Lagonisi and Saronida, forcing people to flee their homes.

A mayor told Greek television that more than 7,000 acres of land was reduced to ashes along a coast, where many Athenians have holiday homes.

"(I only have) my bathing suit which I swim in, nothing else, and this shirt, I have nothing else, I don’t even have other shoes. Nothing. I am finished," said Giorgos Nikolaou, 89, who saw his house in Lagonissi severely damaged by the fire.

A thick layer of white smoke was visible from Athens earlier on Tuesday as a third blaze burned near the seaside resort of Loutraki, about 80 km west of the capital.

The Greek meteorological service has warned of a high risk of fire this week, just as the country is recovering from the first major heatwave of the summer. A second heatwave is forecast for later this week.

Greece still has memories of a wildfire disaster in 2018, when a blaze killed 101 people in the seaside town of Mati, east of Athens.

(Reporting by Angeliki Koutantou and Stelios Misinas, Additional reporting by Lefteris Papadimas; Editing by Simon Cameron-Moore and Sharon Singleton)