Amid religious fervor and gaitey Chhath Puja is being celebrated in Bihar, Jharkhand and eastern parts of Uttar Pradesh. AIR Patna correspondent reports that the whole atmosphere is reverberating with devotional Chhath songs. On this occasion, people fast for 36 hours and pay oblations to Sun God.Devotees standing in knee deep water on the banks of rivers, ponds and water reservoirs will pay oblations to the setting Sun this evening. After paying oblations to the rising Sun tomorrow morning the chhath festival will come to an end.Chhath is celebrated to thank the Sun God for bestowing the bounties of life and prosperity on the earth. It is believed that the wishes of those who observe the Chhath festival with serenity and purity of heart are fulfilled.Meanwhile, security arrangements have been tightened along several rivers and ponds in Patna and adjoining districts in view of heavy turnout of devotees for the mass festival, Chhath Puja, which is celebrated with much fanfare in the state.In the national capital Delhi, several ponds and rivers are tastefully decorated on the occasion of the chhath puja.AIR correspondent reports, in view of last year's rush, security arrangements have been tightened along several rivers and ponds in the city.