A hand grenade exploded early on Saturday morning at the residence of opposition Asom Gana Parishad (AGP) candidate Dulen Nayak, at Moriani in upper Assam's Jorhat district, the police said.
Though the house was damaged in the blast, no one has been injured in the explosion that occurred at about 4.10 AM. Nayak said he heard a loud sound and found his window panes broken and the roof of the sitting room damaged by the blast.
Police sources said unidentified miscreants hurled the grenade at Nayak's house near Kathalguri tea estate.
Investigations were on to know the culprits and their motive.
The AGP contestant accused the ruling Congress of being responsible for the explosion, but the Congress denied the charge.