New Delhi, Sept. 26 -- The National Investigation Agency (NIA) has arrested two more persons in connection with an improvised explosive device (IED) blast on the premises of Nalagarh police station in Himachal Pradesh's Solan district on January 1 this year, officials said on Friday.

The explosion took place near the outer wall of the police station adjoining the room of an investigating officer. A case was initially registered in this connection by state police, before the NIA took over the probe on May 8, they said.

The agency had earlier arrested six accused in the case, namely Mahavir Kumar alias Kaka, Ajay Mehra, Manpreet Singh alias Mani, Arshdeep Singh Kandola alias Arsh Kandola, Karanpreet Singh and Diljot Singh Saini, the NIA s...