The seizure was made after the police intercepted a mini-truck carrying the detonators and the explosives near Raghunathpur in the district.
"We have seized the detonators and gelatine sticks and detained the driver and another person in this regard. They have claimed that the explosives were meant for a stone crushing unit. We are looking into all the details," Superintendent of Police (Purulia) Sudheer Kumar Neelakantam said.
The seizure of explosives, came in the wake of the Oct 2 explosion in a house in Burdwan district in which two suspected militants were killed.
The National Investigation Agency (NIA), probing the Burdwan explosion, suspects the involvement of Bangladesh's Jamaat-ul-Mujahideen.