Manipur Chief Minister Okram Ibobi Singh's residence was attacked by the proscribed People's Revolutionary Party of Kangleipak on Tuesday.
The outfit's spokesman R Meitei said in Imphal on Wednesday that PREPAK had hurled bombs inside Singh's residential premises late on Tuesday night to protest the alleged corruption and violation of human rights in the state.
"We have attacked the chief minister's residence also to protest the killing of our cadre by police on November 13," he added.
A large number of security personnel, including the Central Reserve Police Force and police, have been deployed in front of the chief minister's residence.
Police said they had no clue how the bomb was thrown inside the chief minister's residence. However, no one was injured.
Senior bureaucrats and police personnel had rushed to the spot on Tuesday to inquire into the incident.
Singh was in New Delhi when the incident occurred.