Rajbiraj, May 12 An improvised Explosive Device went off at Survey Office in Saptari headquarters Rajbiraj today. The bomb exploded at the office garage at around 4:00pm. A motorcycle and a cycle were damaged in the explosion. The explosion blew away the roof of the office building and the garage walls have developed cracks. No human casualty was reported as the incident happened when there were no service seekers at the office. A police team has taken the survey office under control and begun investigation into the incident. Meanwhile, an underground armed Tarai outfit Akhil Tarai Janatantrik Tarai Mukti Morcha has taken responsibility for the incident. Issuing a press statement after the incident, ATJTMM Coordinator Jay Krishna Goit said that his outfit had exploded the bomb to warn against rampant corruption at the survey office.