Security forces were on Sunday put on heightened alert across the country and crack anti-terrorist commandoes were positioned at vital installations like nuclear plants and airports in the run up to the Independence Day after intelligence reports warned of possible suicide attacks.
The threat this year is believed to be mainly from Bangladesh-based Harkat-ul-Jehadi Islami and Jamiat-ul- Mujahideen Bangladesh, who are suspected to have entered into an alliance with the banned SIMI, official sources said.
Top officials of the Union home ministry and Intelligence Bureau met on Sunday after a full dress rehearsal for the Independence Day celebrations at the historic Red Fort and decided to deploy more plainclothes personnel in public areas like markets.
The national capital, which will witness the main celebrations, was virtually turned into an impregnable fortress with gun-toting personnel of Delhi Police and paramilitary forces seen guarding markets, railway bridges and tracks and flyovers.
No vehicular movement, except in extreme circumstances, will be allowed in the vicinity of the Red Fort on Tuesday when Prime Minister Manmohan Singh unflurs the national tricolour and addresses the nation from the ramparts of the Mughal-built monument.
These steps were taken following intelligence reports that terrorists were planning to carry out suicide attacks at Shantivan, the memorial of first Prime Minister Jawaharlal Nehru, and Chandni Chowk in the old quarter of Delhi.
The sources said militants are believed to have been camping in the national capital since April to plan such attacks. "The advantage of surprise is usually with militants but we are trying our best," a senior security official said.
Elite commandoes of the National Security Guard and Indo-Tibetan Border Police will guard the Red Fort, where political leaders and citizens will witness the Prime Minister unfurling the triclour.
Helicopters will criss-cross the skies when the Prime Minister addresses the nation and radars of the civilian air traffic control and Indian Air Force will be used to keep an eye on the airspace over the capital.
Sharp-shooters have been positioned at high-rise buildings in Delhi and quick reaction teams of the Central Industrial Security Force deployed at the Indira Gandhi international airport.
Several people were detained in the walled city for questioning and Delhi Police, along with spotters from Jammu and Kashmir Police, searched guesthouses at Nizamuddin, Karol Bagh and Jungpura area besides keeping a strict vigil at the airport, railway station and bus terminals.
The extra security came after intelligence agencies alerted authorities of possible suicide attacks at these facilities.
Key facilities in Bangalore and Hyderabad, the IT hubs of the country, were also given extra security cover following reports that militants of Pakistan-based Lashker-e-Taiba (LeT) might target them.
In Jammu and Kashmir, the state government asked politicians to restrict their movements.
Through unofficial emissaries, the Centre has urged the ULFA, believed to be planning attacks on railway stations and oil infrastructure in the northeast, to desist from creating trouble.
Intelligence reports about the landing of RDX along the coast in Gujarat prompted the government to put the state on high alert.
The authorities have increased the number of security personnel deployed along highways and railway stations in the state to ensure that the explosives are not smuggled to other places.
An advisory has been sent to 13 states affected by Maoist violence to maintain a tight vigil as Naxals might try to target civilians especially in Jharkhand, Bihar, Chhattisgarh and Orissa.
As a result, additional CRPF companies have been deployed in tribal areas of these states, including violence-hit Dandewada district of Chhattisgarh.