An elaborate ground-to-air security blanket enveloped the capital on Thursday with thousands of armed personnel keeping a tight vigil to thwart any possible terror strike on Independence Day.
Security personnel from Delhi Police and paramilitary forces have been deployed in and around the city, especially near the Red Fort from where Prime Minister Manmohan Singh unfurled the tri-colour and addressed the nation for the 10th consecutive time.
Central security agencies last week had given inputs to police that Pakistan-based terror outfit LeT may try to target markets or places of strategic importance in the city.
In view of the threat, security personnel have been deployed at the airport and at market places, railway stations, inter-state bus terminals and metro stations.
Security has been further beefed up in the New Delhi area.
Hundreds of CCTVs have been installed in and around Red Fort with sharpshooters from NSG deployed on high-rises near the 17th century Mughal monument, officials said.
At least 80 companies of security forces (around 6,000 personnel), along with other security personnel in plain clothes, have been deployed at Red Fort and in its vicinity, said a senior police official.
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.
Specialised units like Quick Reaction Teams, SWAT and Vajra were also deployed.
A no-fly zone was put in place around the Red Fort.
Besides patrolling of the skies by helicopters, an air defence mechanism put in place.
Delhi Police carried out intensive checks at all the border points. Vehicles entering the city were randomly checked.