Communist Party of India-Maoist ultras blew up a stone-crushing plant of Bharatiya Janata Party's former Bihar president Gopal Narain Singh in the extremist-hit Rohtas district in the early hours of Monday, police said.
Scores of heavily armed Naxalites descended on the plant at Karwandia around 0100 IST, forced the labourers to vacate the place and blew it up with dynamites, they said.
They also set fire to Singh's office at the plant, police said.