A thick security blanket was thrown at strategic places across the country on the eve of 60th Republic Day and a surface-to-air shield put in place in the national capital, where the main celebrations will be held.
Mobile hit teams, anti-aircraft guns and sharp-shooters of the elite NSG will be deployed at various locations while paramilitary and Delhi Police commandos will keep a tight vigil along the route of the Republic Day parade during which President Pratibha Patil will take the salute.
It would be for the first time that the prime minister will not be participating in the celebrations since Manmohan Singh is in the hospital.
Nearly 20,000 gun-toting policemen fanned out across Delhi, stepping up the security measures especially in the backdrop of Mumbai carnage, which claimed over 180 lives.
Security at important public places and vital installations, including the Delhi Metro stations, railway stations, bus terminals and crowded marketplaces have been tightened.
Electronic surveillance has been increased and extra security cover extended to all the religious places in the capital and air space been closed for traffic.
In Bihar, in the wake of Maoists' call to boycott Republic day celebrations, the entire state has been put on high alert and security increased along the porous Indo-Nepal border.