AGIA ELENI, Greece — Sparks leapt from a glowing carpet of coals as Agia Eleni's firewalkers strolled barefoot across it.

Crowds in the village of Agia Eleni, near the northern Greek town of Serres, gathered to watch the firewalkers, known as "anastenarides" in Greek, mark the May 21 feast day of Saints Constantine and Helen. Some ran while others walked across the burning embers. A repetitious melody from drums and lyres rolled on in the background.

The ritual, along with the two icons of the saints held during the fire-walk, was brought with refugees from the village of Kosti in what is now southern Bulgaria after a population exchange in the early 20th century.

References to firewalking have been traced back to the ancient rites of Dionysus, the Greek god of revelry. But the beginning of the current tradition is unknown. Legend holds that at some point, voices crying for help came from a burning church in Kosti. The faithful believe it was a call from the icons, which were rescued.