Itahari, July 4:

An unidentified gang detonated a pressure cooker bomb in the land revenue office here today. The bomb was placed in a toilet adjoining the office building.

The blast that occurred around 1:30 pm damaged the roof of the toilet.

Irfan Khan, Sunsari in-charge of the Janatantrik Tarai Mukti Morcha-Jwala Singh, owned up the blast over the phone. He said the blast was carried out to warn the office employees, who had refused to pay donation to the Morcha. Security has been beefed up in the land revenue office after the explosion, police said.