minister Ibobi Singh's house in which there was no casualty.
Unidentified ultras had exploded the grenade inside the high-security residential complex late last night when Singh and his family members were present, police said.
A spokesman of the militant outfit PREPAK-P has claimed responsibility for the attack ahead of the independence day celebrations which the outfit along with six others have called
for a boycott.
Meanwhile, security measures have been tightened at VIP complex here at Babupara housing residence of Singh and other senior cabinet ministers.
CORCOM have been boycotting independence and republic day functions for more than three decades in protest againt Manipur's merger with the Indian union in 1949, sources said.
They said police and security posts at outlying areas have been put on alert to intercept movement of armed insurgents.