Military precision blended seamlessly with cultural diversity at India's 66th Republic Day parade Monday where US President Barack Obama was the chief guest.

Heavy armour, marching contingents of the armed forces and the paramilitary and police forces interspersed with brass and pipe bands - tableaux depicting the multifarious heritage of this vast land and schoolchildren dancing merrily in spite of the chill marked the event, crowned by a flypast that many apprehended would not happen due to the weather.

For the first time, an all-women's contingent drawn from the three services featured at the event, while the Indian Army, the Indian Navy and the Indian Air Force also fielded all-women contingents.

Earlier, Prime Minister Narendra Modi drove to India Gate to lay a wreath at the Amar Jawan Jyoti memorial to the unknown soldier.

He later drove back to the saluting base at Rajpath to welcome Obama and President Pranab Mukherjee, who took the salute at the two-hour parade.

Before it commenced, Mukherjee handed over posthumous Ashok Chakras - the nation's highest military award in peacetime - to the widows of Major Mukund Vardarajan and Naik Neeraj Kumar Singh, who were killed in counter-insurgency operations in Jammu and Kashmir.