Suspected militants exploded a grenade at the residence of executive director of rural development department C Hangsing at Churachandpur last evening injuring his younger brother and his granchild.
Hangsing and his other family members were present when the grenade exploded at around 8 p m, the sources said.
In another incident, unidentified militants exploded a grenade at a public playground at Nongren area in Imphal east district late last night, the sources said adding that no one was injured.
In yet another incident, suspected militants exploded a grenade at the house of an assistant engineer of public health engineering department Ibochou Singh late last night at Lamphel area in Imphal west district, the sources said adding that no one was injured.
Police said they would investigate whether the explosions were related to monetary demand of militant outfits from some individuals. No individual or group has claimed responsibility.