IMPHAL, July 18 - In protest against the killing of excise superintendent T Babumacha by the proscribed People's Revolutionary Party of Kangleipak (PREPAK) members, hundreds of protesters on Saturday last staged a mass rally here. The rally was, however, stopped by the police at Khwai Nagamapal. Later, the rallyists organised a meeting at Khurai Lamlong Bazar. Babumacha was kidnapped and killed by PREPAK activists on July 8 at Takyelpat about three km west of Imphal town.