Acting on a tip-off, police conducted a raid last night in Karvandia area under Sasaram Muffasil police station in the district, Rohtas Superintendent of Police (SP) Chandan Kumar Kushwaha said.
The arrested persons have been identified as Anupam Kumar, Rakesh Kumar and Ramjanam Pal, all from different villages in the district.
"The three were arrested from a dilapidated house and they led us to the cache of explosive, which was hidden beneath rock boulders at Uttar Pahar in Wazirganj," the SP said.
He said such explosives are either used in illicit mining activities or for violence by Left Wing Extremists.
The explosives are procured from the neighbouring states like Uttar Pradesh and Jharkhand, he added.