ATHENS, Greece – A Greek monastery clanged its bells in warning Monday as an out-of-control wildfire raced down a mountainside, elderly nuns were evacuated from its threatened convent and the remains of Saint Ephrem were removed to a safer location.

At the Saint Ephrem Monastery near Nea Makri, north of Athens, buildings were silhouetted against a red sky lit up by the glow of nearby wildfires. Workers shoveled sand and sprayed areas with limp garden hoses in apparently fruitless attempts to battle the inferno.

"The flames were 30 meters (100 feet) high," said one of the dozen nuns evacuated, wearing a black habit and a surgical mask to ward off the smoke and grit. "Thankfully they came and rescued us."

For the fourth straight day, exhausted Greek firefighters battled around the clock to try and contain massive blazes north of Athens. To their relief, more water-dropping planes and firefighting help arrived from other European nations.

Six major fires were burning across Greece, including blazes on the islands of Evia and Skyros in the Aegean Sea and Zakynthos in the west. But the most dangerous was the fire near Athens, which started north of the Marathon plain and spread over Mount Penteli on the northern edge of Athens.

Crews tried hard Monday to push the fires back from the outskirts of the Greek capital, with 17 water-dropping planes and helicopters swooping over flames near populated areas. They were joined by up to 2,000 firefighters, military personnel and volunteers.

But fed by strong winds, the flames still spread and threatened property further to the north, where the nuns were rescued and residents defended their homes with only buckets of water.

"We making every possible effort to limit the boundaries of the fire," said Fire Service spokesman Yiannis Kappakis.

Fires north of Athens have razed about 58 square miles (37,000 acres or 15,000 hectares) of forest and brush, damaged or destroyed homes, and forced thousands to temporarily flee their homes. Popular tourist destinations have not been affected.

At least five people were being treated for burns and several dozen had reported breathing problems, but no injuries were serious, Health Ministry officials said.

Firefighting planes and helicopters from France, Italy and Cyprus were operating outside Athens, with more planes due to arrive later Monday and Tuesday from Spain, Turkey and the European Union, Civil Protection Agency officials said.

Several other EU countries had also offered help, they said.

There were no firm estimates on the thousands of residents who evacuated or the scores of homes that were torched. Athens regional governor Yiannis Sgouros said damage would be assessed once the fires were put out.

"There are some signs of optimism but no letting up of the firefighting effort," he said.

Prime Minister Costas Karamanlis toured the fire-affected areas on Sunday amid strong criticism of his government's response to the emergency by conservation groups and municipal officials.

Critics said the government had not reformed its forest-protection plans even after huge fires swept through southern Greece two years ago, killing 76 people.

"A compete overhaul is required in the way we deal with forest fires ... There is no sign the (government) is moving the right direction," Dimitris Karavellas, director of the environmental group WWF in Greece, told the Associated Press.

He said state planners had made insufficient use of volunteer groups and had failed to crackdown on rogue developers who build homes illegally in burnt forest areas.

Government spokesman Evangelos Antonaros insisted Monday that the firefighting effort was "well coordinated,"

"From the first moment, (we had) the presence of personnel on a large scale," he declared.

Antonaros also disputed estimates by municipal officials that scores of homes had been destroyed or seriously damaged and said the number of people involved in state-organized evacuations was "limited," with most having returned to their homes.

Fires raged, meanwhile, at the coastal town of Nea Makri and nearby Marathon — site of one of ancient history's most famous battlegrounds — to the northeast of the capital and at Vilia to the northwest.

The blaze at Nea Makri tore down a hillside toward houses, where volunteers with water-soaked towels wrapped around their necks beat back the flames with tree branches.

Fires also continued to threaten the ancient fortress town of Rhamnus, home to two 2,500-year-old temples.

Over the weekend, authorities evacuated two large children's hospitals as well as campsites and villages outside of Athens.

Officials have not said what started the fires. Hundreds of forest blazes plague Greece every summer and some are set intentionally — often by the unscrupulous land developers or animal farmers seeking to expand their grazing land.

"There is still a state of ambiguity as to where the forest starts and residential areas end. As long as this persists, there is an incentive for starting fires," Karavellas of WWF said. "These are areas that are always being eyed for development."

Greece's National Weather Service said strong winds are expected to ease Tuesday.