In the aftermath of the Patna serial bomb blasts, raids were being conducted in several areas of neighbouring Jharkhand.

Three persons detained after the blasts yesterday were released after interrogation last night, a senior police officer said in Ranchi.

Police recovered black powder, materials used to make IEDs, pressure cookers and extremist literature during the raids.

The Home Ministry also asked five poll-bound states to beef up security in election rallies, especially those being attended by top leaders.

The MHA has also asked states and Union Territories to keep strict vigil on sensitive places, markets, religious sites, railway stations, bus terminus and in other vital installations besides deploying adequate forces for their security.