"There shall be special checking of all vehicles, both private and commercial, entering the city from neighbouring states through border entry points," said Additional Commissioner of Police (Traffic) Anil Shukla.
Besides Delhi Police personnel and commandos, security officials in plain clothes and snipers will also be deployed around the Red Fort. At least 80 companies of security forces (around 6,000 personnel) will be deployed at the Red Fort and the surrounding areas, said the official.
"A team of snipers, National Security Guard (NSG) commandos along with Delhi Police will man the fort in a multi-tier security arrangement," he added.
Delhi Police and traffic police personnel will be spread out across the city to secure important places as well as entry and exit points at "vulnerable locations". All high-rise buildings, hotels, guest houses, markets and restaurants in Paharganj, Jama Masjid and areas near the Red Fort will be under the police scanner.
Even rickshaw-pullers and vendors in the area have been asked to keep a lookout for suspicious objects and people, police said.
"Intensive checking drives have been started at the airport, railway stations, Metro stations, bus stops, markets, malls and the border areas," said the officer.
Intensive drives have also been conducted for verification of tenants, servants, occupants of guest houses, dealers of used scooters and cars, cyber cafe users and cycle sellers across the city, he said.
"We have received a letter from IB (Intelligence Bureau) about a threat from a terrorist outfit ahead of Aug 15," a police source said.
"All the neighbouring states have also been alerted and security has been beefed up at border check posts, railway stations, metro and all interstate bus terminus," said a senior Delhi Police officer.
Delhi Police Commissioner Bhim Sain Bassi held a meeting of senior police officers from neighbouring states on Aug 7 to discuss security-related issues.
"The objective of the meeting was to share terror related intelligence and inputs about various extremist outfits and their designs," Delhi Police spokesperson Rajan Bhagat said.