Rautahat: The Maoists set fire to a District Forest Office building at Chandranigahapur on Wednesday causing damage of Rs 500,000. District-based security sources said 20-25 armed Maoists overpowered guard Chandra Bahadur Magarati and set the office on fire by spraying petrol. The top storey was completely damaged in the fire and the Maoists also made away with a computer set. A joint team of security forces has launched a massive search.