Guwahati, June 27 (ANI): Amid the clash of cymbals and blowing of conch shells, saffron-robed Hindu holy men performed mystic rituals to celebrate the annual fertility festival at the revered shrine of Goddess Kamakhya in the northeastern Indian city of Guwahati. The four-day festival also known as 'Ambubachi fair', which began on June 22, is held with the grand arrival of monsoon in Assam. As per Hindu mythology, Kamakhya is one of the most mystical religious sites in India. The festival is based on the belief that during this period the goddess goes through her annual menstrual cycle - symbolizing fertility. The temple has no image of the goddess but a natural underground stream which emanates from a fissure in a rock that symbolizes Lord Shiva's wife Sati. During the time of the festival the water turns red due to iron oxidation resembling menstrual fluids. The main gate of the temple remains closed for the visitors for three days and devotees wait outside the temple till the fourth day, when the temple is opened. The festival is also a major draw for the practitioners of occult with a large number of pot smoking ascetics descending on the shrine, lending a mystic aura to the whole atmosphere. Holy men and priests danced to religious hymns as they camped outside the temple, wa