With intelligence inputs warning of threats posed by LeT and other militant groups, security establishments in Delhi and the state capitals went on top alert on Monday, putting in place a ground-to-air apparatus to thwart any attempt to disrupt the Republic Day celebrations.
A heavy security blanket was thrown around the capital with snipers and mobile hit teams fanning across the city and nearly 15,000 police and paramilitary personnel being deployed to guard the 8-km-long route of the Republic Day parade and other key installations. Anti-aircraft guns have also been stationed in certain crucial areas.
The security measures have been planned keeping in view intelligence inputs including Pak-based Lashker-e-Taiba acquiring over 50 para-gliding equipment which could be used to launch an air-borne suicide attacks.
A close vigil has been mounted in Jammu and Kashmir to ensure that Republic Day functions in the border state passed off peacefully.
Strict security arrangements have also been made in Naxal-hit regions and in the eight north-eastern states where calls for boycott of Tuesday's functions have been given by some militant groups.
In Delhi, a ground-to-air security apparatus has been put in place for the celebrations and a tight vigil was being maintained between Vijay Chowk and Red Fort through which the parade showcasing the country's diversity and military prowess will pass through.
"192 companies (over 15,000) police and paramilitary personnel are being deployed on the parade route," Delhi Police Commissioner Y S Dadwal told reporters in New Delhi. This is in addition to resources available with New Delhi and Central Delhi police districts.
"Pickets are everywhere and extensive checking is being carried out," Dadwal said.
A senior police official said a multi-layer security ring will be put in place at Rajpath, where President Pratibha Patil will unfurl the tricolour tomorrow and take the salute of marching contingents.
In Mumbai, which witnessed terror attacks in November 2008, and other parts of Maharashtra, a high alert has been sounded to prevent any terror strike.
Elaborate security arrangements have also been made in Naxal-infested areas in view of Tuesday's bandh calls given Maoists in Maharashtra and other states.
"We are taking all precautionary measures to ensure peaceful celebrations on R-Day," NS Jagtap, spokesperson of the police in Maharashtra's Gadchiroli district, which has been hit by the Naxal menace, said.
A senior police officer in Mumbai said all district police chiefs have been asked to be on top alert. They have also been asked to co-ordinate with Coast Guard, Navy and Traffic police and Railway police forces wherever needed.
Security has been tightened at railway stations, airports and major installations in Mumbai, police said.
Mumbai Joint Police Commissioner (Law and Order), Himanshu Roy said apart from ground security in the city, aerial vigilance is also being given the right priority.