Indian forces have killed the Maoist rebel chief and dozens of other fighters, the country’s home minister says, calling it a decisive blow in a decades-long conflict.

India has been waging an all-out offensive against the last remaining groups of the Naxalite rebellion, a far-left Maoist-inspired fighting movement that began in 1967.

Home Affairs Minister Amit Shah announced on Wednesday that Nambala Keshav Rao, alias Basavaraju, was among 27 rebels killed by security forces in central India’s Chhattisgarh state.

Shah identified Rao as the general-secretary of the banned Communist Party of India-Maoist group and the “topmost leader and the backbone” of the Naxal movement.