Bulgari, Bulgaria - As night falls over the remote village of Bulgari, a handful of men and women prepare for "Nestinarstvo", an ancient fire dance that practitioners fear is being trivialised by tourism.
"It doesn't matter how hot the embers are. You just switch off and feel or hear nothing but the drum and the bagpipe," says 54-year-old Mihail Georgiev, one of the "Nestinari" or fire-dancers.
He steps barefoot onto the red-hot coals but like other Nestinari apparently suffers no pain or burns during the ritual -- something that remains a mystery to doctors.
His forehead is dotted with sweat and his shirt sticks to his back, but Mihail claims his feet are ice-cold as he dances, clutching an icon of Saints Constantine and Elena close to his face.
Despite numerous examinations, a team from the Bulgarian Academy of Sciences could only ascertain that the dancers' body temperature dropped substantially to around 31 degrees C (87 F) compared with the average 37 degrees (98.6 F).
"Saint Constantine is with me when I dance and I am not afraid," says another dancer, 17-year-old Kostadin Mihaylov from the nearby village of Brodilovo in the country's southeast.
It is June 3, the orthodox feast of the two saints who -- so the Nestinari believe -- have summoned them to dance and protect their feet while they tread the burning coals.
The dancing lasts more than 10 minutes, and draws hundreds of tourists who travel to the remote and sparsely populated Strandzha mountains each year to watch the event.
After the Nestinari leave, swearing and cries of pain can be heard as a few dozen raucous tourists attempt the feat themselves. Many of these onlookers are foreign backpackers or hippies -- and not entirely welcome in the villages.
"This used to be a sacred ritual, practised by an extremely small and closed community who live in this part of the Strandzha mountain. It's a pity that it has turned into a tourist attraction," the director of the Strandzha national park, Stefan Zlatarov, told AFP.
Several elderly villagers also grumble about their ancient cult being "turned into show business".
According to historian Valeria Fol, "Nestinarstvo" dates back to the ancient Thracians who lived in the region that is now present-day Bulgaria from 4,000 years BC to 300 AD.
With the advent of Christianity, the Nestinari adopted the Eastern Orthdox saints, blending the new religion with the old.
"The saints were just a Christian icing over a splendid Thracian candy," Fol told AFP.
The ritual is also observed in a number of villages in northern Greece, where some Bulgarian Nestinari fled in the early 20th century. There, the "Anastenarides" as they are called in Greek, perform the rite on May 21, the date of the patron saints' day in Greece.
Both the Bulgarian and the Greek Orthodox churches, however, frown upon the ritual, saying the dancers are possessed by the devil.
While the ritual fire dance was allowed to continue during communism, largely as a tourist attraction, an accompanying devotional ceremony traditionally held two days earlier fell into abandon.
In an attempt to recapture this religious spirit, the Strandzha national park authority instigated a revival of the ceremony four years ago.
Since then, the Bulgarian Nestinari and Greek Anastenarides have gathered in a remote mountain clearing that they regard as their "homeland" to perform the ceremony away from the intrusive eyes of tourists.
Legend has it that all Nestinari once lived in a single village surrounded by five "holy" springs.
In today's ritual, drums beat and bagpipes drone on as the icons are carried in a small procession to the clearing. They are then washed with water from the springs, draped in crimson cloth and placed on small wooden platforms on the ground. Home-made bread, flowers, and other small gifts are piled up as offerings to the saints.
Lambs are slaughtered early in the morning and the meat is prepared and cooked for a sacrificial meal afterwards.
This year, the Greek Anastenarides could not attend because one of their elders was too ill to travel.
But the Bulgarian Nestinari said they would wait for them again next year as the annual reunion is the only way to keep their tiny scattered community from dying out.