"We have knocked down many and we will catch the rest," Roy said, when asked about the strategies being taken to arrest the people behind the terror acts in the metropolis.
The DGP said security along the coastline was not adequate and much needed to be done to make it foolproof.
"Coastal security has been a matter of great concern. The government has been conscious about this. Still, perhaps, we have not been able to meet the challenges. We definitely need to improve. That is an area which is a matter of great concern," he said.