Imphal, November 20: A hand grenade lobbed by activists of the proscribed outfit PULF exploded at the office of World Vision, India (Area Development Programme, Ukhrul) at Maringlane here under Porompat Police Station at around 3.40 am today.

The explosion caused damages to one Bolero (MN01-K/6109), one Nova, one Scooter and one Glamour mobike stationed in the office complex.

The office complex is being rented out by Fisheries Commissioner Lakher.

Claiming the responsibility for the blast, finance secretary of PULF Raj Khan said the bomb explosion was only the first warning to the NGO for the latter's disregard to the invitation of the outfit for a talk.

In case the NGO does not heed the warning, the outfit may be constrained to strike with bigger impact next time, Khan said, while asking the leader of the NGO to surrender to the outfit at the earliest possible.

Suspected underground activists also reportedly attacked a convoy of 19 Assam Rifles by exploding a remote-controlled bomb planted in the middle of the road between Gwaltabi and Mahadeva under Litan Police Station at around 8.40 am today.

There is no report of any casualty in the attack.

In another incident, a bomb expert of the State Police Department retrieved a remote-controlled bomb which was found planted by suspected underground activists at Langthabal Hao Lamkhao under Singjamei Police Station at around 3 pm today.

The bomb experts detonated the bomb safely at around 4.30 pm.