The operation was conducted by paramilitary CRPF along with state police forces in the Rudrapur forests of the district.
"Numerous bags weighing 3,400-kgs of ammonium nitrate were seized during an operation in the district. Also, 700 electronic detonators were seized," a senior official here said.
Thirteen large bundles of iron wire mesh were also seized during the same operation, the official added.
Ammonium nitrate is extensively used in Maoist violence affected areas to prepare Improvised Explosive Devices (IEDs) to target security forces and hence such a large seizure of this chemical from one spot is worrisome, the official said.