An elaborate ground-to-air security apparatus was put in place in the city, especially near Red Fort where Prime Minister Manmohan Singh unfurled the tri-colour and addressed the nation for the eighth consecutive time.
Security agencies left no stone unturned to ensure incident-free Independence Day celebrations even though there was no specific intelligence input about a possible terror strike.
The Union Home Ministry has already issued a country-wide alert asking states to tighten security at sensitive locations and installations to thwart any attempt of terror strike. This year's celebrations come a month after terrorists struck in Mumbai.
"Elaborate security arrangements have been made. Personnel from Delhi Police and paramilitary have been deployed for security," a senior police official said.
Around 40 CCTVs have been installed in and around the Red Fort to ensure peaceful celebrations while sharpshooters of the NSG deployed on the high-rises near the 17th century Mughal monument.
Besides the Red Fort, the official said, intense vigil was being maintained on key installations like Parliament complex, international airport, railway stations, inter-state bus terminals and Metro stations.
"The localities around the Red Fort have been sanitised before the event and informers were deployed to keep a check on any movement of anti-national elements," the official said, adding specialised units like Quick Reaction Teams, SWAT and Vajra were deployed.
A no-fly zone was put in place around the Red Fort for the nearly 90-minute function.
Besides patrolling of the skies by helicopters, an air defence mechanism was also kept in readiness around the venue to thwart any terror attacks.
Delhi Police carried out intensive checks at all the border points.There was, however, no sealing of borders this time. "We conducted random checking at borders so that there were no long queues at the borders," the official said.