Two fire brigade helicopters collided mid-air in Greece on Sunday, as firefighters continued to battle fierce wildfires around the Gulf of Corinth.

The fire service said the two aircraft collided in the Psatha area, just to the west of the capital, Athens, adding that search and rescue teams were "immediately mobilized to locate and assist the crews."

Television footage showed one of the helicopters explode and plunge to the ground in flames after an apparent rotor collision.

Greek public broadcaster ERT reported that the crew of one of the helicopters had been found and were safe. The fate of the crew of the second helicopter initially remained unclear.

Greece wildfires: 'Extremely difficult' days ahead, says PM

The accident came as Greek firefighters continued to battle wildfires on multiple fronts. Three firefighters died in recent days in the line of duty, two in Crete and one in the Peloponnese.

The fires are being exacerbated and spread by winds of up to 100 kilometers (60 miles) per hour, with Prime Minister Kyriakos Mitsotakis warning of "extremely difficult" days ahead.

"When the winds blow with such force, even the dozens of aircraft we have at our disposal cannot operate safely," he wrote on social media.

"There are moments when nature and the intensity of weather phenomena surpass any human planning and any operational capability."

Just to the north of Psatha in the neighboring town of Porto Germeno, nearly 500 firefighters were attempting to keep a blaze from approaching the western outskirts of Athens after it scaled a mountain overnight.

Footage released by Greek police showed officers going door to door on motorcycles in the nearby hilltop village of Agios Nektarios, sounding sirens and shouting "Is anyone there?" as they urged residents to evacuate.

On Friday, firefighters evacuated 254 people by sea – often the last escape route for isolated coastal communities – followed by another 12 on Saturday.

"We could not believe what we were seeing," Nikos Georgopoulos from the laboratory of forest management at the Aristotle University of Thessaloniki, told state TV channel ERT. "The fire spread extremely rapidly."

Greece: man arrested on suspicion of arson

Further west and on the opposite side of the Gulf of Corinth, some 100 firefighters were fighting another blaze in Aigialia in the northern Peloponnese region.

Meanwhile, a 44-year-old man was arrested on Sunday on suspicion of deliberately starting a new fire which broke out late Saturday on the popular Ionian Sea island of Cephalonia.

The National Observatory's climate tracker meteo.gr said early estimates indicated that over 6,500 hectares (16,000 acres) had been burned in separate fires around the Gulf of Corinth.

Meteorologist Theodore Giannaros said that the fires around Porto Germeno are "likely, if not almost certain … [to] be classified as a megafire."

Edited by: Jenipher Camino Gonzalez

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