An excavator has been set on fire by a group of unidentified masked persons at a bridge construction site in Gaidatar, Chandrapur Municipality-3 of Rautahat district on Saturday night. After taking a site security guard under control, the group of 5 to 6 persons had torched the excavator, which had been brought there for the undergoing bridge construction over Chadi Khola connecting Chandrapur and Gaidatar of the district. A team of police was deployed to the incident site; however, the fire had already destroyed the heavy construction equipment before it could contain the fire, according to the Chandrapur Area Police Office. Police have begun investigation into the case, said SP Yagya Binod Pokharel, adding that those involved in the incident would soon be arrested. Locals have speculated that the Netra Bikram Chand-led CPN Maoist cadres are behind the arson attack, as the bridge construction team had refused to give donations to the party.