NEW DELHI: Over several days in December, the Indian security establishment and the Uttar Pradesh police carried out extensive search operations along the Delhi-Agra route in search of about five Pakistani terrorists.Sources said the hunt for the terrorists was based on specific information, but the intelligence input was not linked to the upcoming visit of US President Barack Obama.The input had said that about five Pakistani terrorists had infiltrated into India via Nepal and were headed towards Agra. Later inputs also showed that they may be hiding in a village close to the Delhi-Agra expressway.Based on the input, security agencies launched a massive hunt for the terrorists. Besides the central agencies, local police was also involved. The search operation lasted a few days. At the end of the operation, no terrorists were nabbed.However, this terror hunt in mid-December may have led to a significant sanitization of the Delhi-Agra expressway, the stand-by route for President Barack Obama's visit to Taj Mahal. And it has made things easier for the Indian security establishment, which is now frantically trying to meet the demands of the US counterparts for ensuring a foolproof visit for Obama.President Obama arrives in India on January 25 morning, and will leave on January 27. Besides, Delhi he would also visit Agra.All the Indian intelligence agencies, Delhi police, some paramilitary forces, Uttar Pradesh police, army and air force are all involved in some way or the other in Republic Day parade, and President Obama's visit.Sources said there are no specific reliable intelligence alerts about any threat to Obama's visit, or the Republic Day parade.However, in recent weeks, the US and Indian agencies have issued several terror alerts. One of them warned about the possible hijack of the Air India flight to Kabul. Another spoke about the possibility of a group of terrorists infiltrating along the Jammu and Kashmir border to strike Indian cities.