The fair originates from the times when emperor Chandragupta Maurya used to buy elephants and horses from across the Ganga.
With the state witnessing serial blasts in Patna and earlier in Bodh Gaya, strict security arrangements have been made.
Saran district magistrate Kundan Kumar said 20 temporary police stations have been opened for the fair.
Policemen have been equipped with hand metal detectors to frisk visitors at the fair. The police were also patrolling in boats in the river.
