A special team of 'terrorist spotters' drawn from a dozen militancy affected Indian states has spread out in the sprawling 4,000-acre Kumbh Mela area to keep a round the clock vigil against a possible militant strike in or around the largest human congregation in Allahabad.

Specially trained in the skill of spotting terrorists, these sleuths will keep an eye for "suspicious" characters.

While he declined to give out details of their deployment, Mela Police Chief Rajeev Sabharwal made it quite explicit that the security personnel were fully geared to tackle any contingency.

While denying any direct terrorist threat to the mela, he said, "Yes we have sounded a general alert. After all with millions landing here over the coming days in what is the single largest gathering of people on this earth, we cannot take any chances, and we are taking every possible measure against any possible terrorist strike."

"As many as 10,000-11,000 policemen will remain on round the clock vigil all over the vast 4,000-acre spread to ensure safety and security of the mammoth gathering. We have also created a special task force of men without uniform," he added.

The large police force includes about 3,000 heavily equipped men drawn from India's ace paramilitary organisations -- Border Security Force and Central Reserve Police Force.

Meanwhile, heavy infrastructure has been put in place to handle routine crime and law and order.

As many as 25 police stations and 25 police outposts have been set up. "We have also created five special camps for 'lost and found' persons," Sabharwal added.