Here are the latest developments:
Two terror suspects have been arrested in Karnataka, two in Hyderabad and 1 from Mumbai. The NIA is reportedly also looking for five more suspects in Hyderabad.
Sources said the people arrested today are not believed to be part of a single module or connected to each other. There were also unconfirmed reports that explosives were recovered from Tolichowki area of Hyderabad.
Some of those arrested are students while the others are employees in various companies.
All of them had been under surveillance for over six months now and the arrests were made amid indications that an ISIS network is coming up across the country, sources said.
Security agencies want to prevent a Paris-style attack, where the terrorists were under surveillance and yet managed to strike. ISIS gunmen had attacked Paris in November, killing 130 people in a cafe, rock concert and other public places.
At a recent security review chaired by Home Minister Rajnath Singh, officials concluded there is a "very real" ISIS threat for Republic Day, when French President Francois Hollande will officiate as chief guest at the parade in the capital.
Yesterday, a letter, reportedly mailed from Chennai and warning against President Hollande's visit, was delivered to the French consulate in Bengaluru earlier this month.
On Wednesday, four men were arrested from Uttarakhand for alleged links to the ISIS. They had been under surveillance for visiting ISIS propagandist sites.
The men arrested yesterday were allegedly planning to attack the ongoing Kumbh Mela at Haridwar in Uttar Pradesh, trains headed there, as well as strategic locations in the national capital, the police said.
The police have warned that they were part of a bigger group. "The national capital faces threat until the entire module is busted," a police officer said.