Suspected militants exploded a powerful grenade at the official residence of a Manipur minister in Imphal who was not present at the time, official sources said on Tuesday.

No one was hurt in the incident.

Two militants, who arrived on a two-wheeler on Monday evening, lobbed the grenade which exploded just in front of the residence of Minister for Agriculture Parijat Singh at Kangla Park in Imphal, they said.

Singh, a senior Communist Party of India leader, was away in his Assembly constituency of Lamlai in Imphal East district at the time of the incident, the sources said.

This was the second time a powerful grenade was hurled at the official residence of the minister in the past five months.

The motive behind the incident was not immediately known, the sources said adding, the police would invesitigate if the incident was connected with any monetary demand from the minister.

It would also invesitigate how the militants entered the VIP area where tight security arrangements were in place.