"It is true that they are students of class VII, VIII and IX, but they are all above 18 years of age," circle inspector of Keshpur, Dibyendu Sarkar, who is the investigating officer in the case, told PTI.
"We will not say what the exact charges against them re, but we have found definite involvement and so we have arrested them," Sarkar said.
The students, Eben Murmu of class VII of Lalgar Ramkrishna Vidyapith, Buddhadeb Patra, a student of class VIII and Goutam Patra, a student of class IX, both of Kantapahari Vivekananda Vidyapith were arrested from Bansbar village which is around 40
km away from the site of the blast.
Another senior officer who is also investigating the blast, said that the students were charged with waging war against the state, conspiracy, attempt to murder, and procuring and use of explosives.
The other three arrested were Lakshmiram Murmu and Sahadeb Mahato of Birbanpur in Salboni and Gopal Karanga of Dharampur in Lagar in the district.
All the six were produced in court and have been remanded to police custody for ten days.