NEW DELHI (Agencies) - India put its airports on high alert Thursday following warnings of possible attacks using hijacked aircraft, officials said, a week after gunmen went on a killing spree in Mumbai. The emergency measures were enacted as Defence Minister AK Antony ordered the armed forces to be on guard against "any terror strikes from the air." All major airports - including Bangalore, Chennai, Hyderabad, Kolkata, Mumbai and New Delhi - were placed on high alert. The Indian Air Force chief, Fali Homar Major told reporters that new intelligence reports had persuaded the authorities to declare an alert at airports. "This is based on a little warning that has been received," he said. "We are prepared as usual." He offered no further details, but an Indian television network, NDTV, said the warning related to what it called a "9/11" plot timed to coincide with the anniversary on Dec 6 of the desecration of by Hindu militants of the Babri Masjid in northern India in 1992. Officials cited intelligence "inputs" that militants may have sneaked into India to try and hijack civilian aircraft. The Bureau of Civil Aviation Security, which is in charge of airport safety, said additional paramilitary troops had been deployed to guard the country's busiest airports. Hundreds of paramilitary troops were on duty at Chennai's international airport, where machine gun bunkers were set up at the entrance gates. Indian Air Force sources said fighter jets were on stand-by across the country to prevent any 9/11-style attacks using hijacked airplanes. "More aircraft have been sent to sectors where we were thin on the ground and so now we are adequately ready to respond to any militant attempt to use hijacked aircraft as flying missiles," a senior air force official told AFP. "Any unidentified aircraft will be challenged from the ground and from the air." India is also likely to deploy batteries of anti-aircraft missiles in "high value areas," the official added. The Centre held a high-level meeting to review the security scenario in the country. The meeting, chaired by Cabinet Secretary K M Chandrasekhar, was attended among others by top brass of the Army, Air Force, Navy, Coast Guard, IB and RAW. The need for a greater coordination among all security and intelligence agencies was stressed at the meeting and for making preparations to counter the threats from terrorists of attacks by air and prevent a repeat of World Trade Centre-type attacks carried out by al Qaeda, sources said. The meeting also reviewed the situation along the Line of Control (LoC) with Pakistan in the wake of reports that its army was on a "high alert" following the Mumbai terror attacks. The top officials discussed plans for beefing up coastal security and hastening acquisition process for systems and platforms including coastal radars and interceptor boats. According to a report carried by The Times, India and Pakistan are at loggerheads as Indian police prepare to use "truth serum" on the lone detained gunman, Azam Amir Kasab, to solve the puzzle over identity. The mystery of the man dubbed has weighed heavily on India's relations with Pakistan as the nuclear-armed neighbours dispute each other's accounts of his origin, and the United States tries to avert a war between them. Rakesh Maria, the Joint Commissioner of Mumbai Police, who is one of the interrogators questioning Azam Amir Kasab, told The Times Kasab has told he was paid 150,000 Pakistani rupees - about $1,900 - for his part in the attacks. Police are also investigating a possible link to the US - a mobile SIM card found with the terrorists which possibly came from New Jersey. Mumbai police claim Kasab is a poor 24-year-old primary school dropout from Faridkot, a village in Pakistan's south Punjab. They assert he has confessed to being recruited by Lashkar-e-Taiba to carry out the Mumbai strikes. Mumbai police claim that Kasab was trained in camps in Pakistan for up to 18 months by ex-army officers. In response, however, Pakistan's government has denied any knowledge of Kasab and has said it cannot find any trace of him in three villages named Faridkot in south Punjab.