A Brigadier and three Lt Colonels alleged to be involved in the incident have been relieved of their duties as further investigations are under way by the Court of Inquiry and the Gampaha magistrate, military spokesman Brigadier Ruwan Wanigasooriya said.
The decision comes in the midst of a visit by the UN Human Rights Commissioner Navi Pillay to the country. She is to meet President Mahinda Rajapaka later in the day.
The Sri Lankan government has argued that the military was acting in self-defence as the protesters threw gasoline bombs. It has announced a compensation for the victims.
Lankan Army chief Daya Ratnayake has constituted a five-member board to investigate into all allegations against the military.
The opposition has held protests highlighting the government's excessive use of force on the peaceful demonstrators ever since the crackdown took place.
