Lagos - Amnesty International says Nigeria's military has killed at least 150 peaceful protesters in a "chilling campaign" to repress renewed demands to create a breakaway state of Biafra in the southeast. Nigeria's military denied "killing of defenseless agitators".

A report on Thursday from the London-based human rights organisation says an analysis of 87 videos, 122 photographs and 146 testimonies shows "the military fired live ammunition with little or no warning" into crowds protesting between August 2015 and August 2016.

A military statement said soldiers "exercised maximum restraint" in response to violent protesters who in one instance killed five police officers. It accused secessionists of "a reign of hate, terror and ethno-religious controversies ... (threatening) national security."

Nigeria's 1967-1970 civil war to create Biafra for the Igbo people killed about one million people.