ATHENS, Greece – A massive wildfire that destroyed homes and forests receded Monday as a multinational airborne effort beat back flames that at one point threatened Athens’ northern suburbs and raged near the ancient battleground at Marathon.

As winds died down late Monday, Greek Fire Brigade spokesman Yiannis Kappakis said there were “no siAgnificant active fronts” left of the fire, which for days has sent a pall of smoke over the capital, plunging parts of it into a brown half-light.

Kappakis said more than 1,000 firefighters and soldiers would remain on duty in case the blazes revived.

“The danger of the fires flaring up again is not yet over,” he said.

Since Saturday the fire has razed some 51,890 acres of pine forest, olive grove, brush and farmland, according to the European Commission’s European Forest Fire Information System. Greek officials say 150 homes were damaged.

Experts warned it would take generations to replace the lost forests, many of which were burnt beyond the hope of natural regrowth.

Thousands of people were forced to flee their homes, and elderly nuns were evacuated from the threatened convent of Saint Ephrem near the coastal town of Nea Makri – carrying the saint’s relics with them.

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

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

Other major fires still burned near the coastal town of Porto Germeno, northwest of Athens, and near villages on the Evia island, east of the capital.

Nineteen water-dropping planes and helicopters – including aircraft from Italy, France and Cyprus – unleashed some 14,000 tons of water on Monday that helped contain the biggest blaze near Athens.

The European Commission said in a statement it was the biggest coordinated emergency operation this year.

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