An NIA team has picked up eight persons for interrogation from a village in Bihar's Munger district in connection with their alleged role in the twin blasts in Hyderabad on February 21.
Two of the eight persons picked by the NIA team were later let off as no no charge could be made out against them, the police said.
The interrogation of six others was going on, the police said.
The NIA team arrived in Munger on Wednesday and picked up the eight persons from Chaurama village and adjoining areas for their alleged role in the Hyderabad blast on the basis of a surveillance report.
The report said that a mobile phone SIM card purchased in Munger on the basis of a fake identity was used by a Malda-based terror suspect for keeping contact with the perpetrators of Hyderabad blast, the police said.
The NIA had put the mobile phone with that particular SIM on surveillance. It sent a team here to question those persons whose names figured during conversation from the said SIM, the police said.
Munger range deputy inspector general of police (DIG) Anil Kishore Yadav said the NIA team visited Munger district last evening and questioned eight persons in connection with their alleged role in the Hyderabad blast, but said no one was detained or arrested by the anti-terror agency sleuths.
The February 21 blasts in Hyderabad had left 16 people dead.