According to police, they stumbled upon the landmines during an operation against Maoists. The landmines were planted over half-a-km and connected through wire.
Police also seized 23 grenades. The landmines were recovered in the Madanpur-Lawapani area under Kisko police station of Lohardagga district which is about 90 km from here.
The recovered landmines were later defused.
Maoist guerrillas are active in 18 of the 24 districts in the state.