The grenade exploded in the housing complex of deputy director of agriculture department, Ph. Rajendro at Kongpal area near here, at around 11 PM, officials said today.
The official and his family members were present at the time of the explosion, but none was injured, they said.
A caller who identified himself as a spokesperson of militant outfit, Maoist Communist Party (Manipur), claimed responsibility for the blast.
Family sources said some militant outfits had demanded a huge sum of money from the official, but declined to name the outfit.
Militants also threw a powerful grenade at a pharmacy near the district hospital at Porompat area in the same district last evening, but it did not explode and was defused, the sources said.
A militant outfit had demanded Rs.1.20 lakh from each pharmacy located near the hospital, they said.
Several social organisations in separate statements urged the authorities to take action against the militants who were extorting money from people and organisations.