It was on May 30 when Agatha Ikefuna, a nurse who lives in Onitsha, a city in southeastern Nigeria, was trapped by a series of military roadblocks.
That's when the chaos erupted.
"I was trying to drop my child in school. There was no movement. They said people were being killed," she told VOA.
Pro-Biafran demonstrators had gathered to honor people who died nearly 50 years ago in the Nigerian Civil War, also known as the Biafra War, when shots rang out nearby.
Some witnesses said it was the police firing on protesters, while others claimed the exact opposite. Ikefuna believed it was thieves who had infiltrated the protest.
Whoever pulled the trigger left dozens of civilians and at least two policemen dead. According to a report released Thursday by Amnesty International, Ikefuna had witnessed only a portion of an estimated 60 killings at various Biafra remembrance events that had taken place in the region that day.
Between August 2015 and August 2016, the London-based human rights organization says, Nigeria's military has killed at least 150 peaceful protesters in a "chilling campaign" to repress renewed demands for a breakaway state of Biafra in the West African country's southeastern corner.
Analysis of 87 videos, 122 photographs and testimony from 146 witnesses show that Nigerian troops routinely "fired live ammunition with little or no warning'' into crowds of protesters, and that hundreds of people have been arbitrarily detained and sometimes tortured.
Responding to questions about the mass killing that occurred on May 30, Nigerian army spokesman Col. Sani Kukasheka Usman denied any "killing of defenseless agitators," insisting that security forces "exercised maximum restraint" in response to violent protesters who had already killed five police officers and wounded several soldiers.
Usman also accuses the secessionists of targeting other tribes in "a reign of hate, terror and ethno-religious controversies ... [that threaten] national security."
A high-level Nigerian military official who asked not to be named told VOA that Amnesty International’s report is not accurate and grossly exaggerates misrepresents events as they unfolded. She also said the Nigerian army investigated the May 30 events and concluded that the Biafra activists were at fault. She said the army plans to hold a hearing to present its findings.
Makmid Kamara, interim director of Amnesty International Nigeria, says the army’s response to the report is to be expected.
"This is a copy and paste response to our allegations," he told VOA. "It’s the same thing that they have been saying for years, because we have been calling on them repeatedly to conduct independent, impartial and thorough investigations into allegations of serious human rights abuses."
Kamara, who personally interviewed witnesses of the violence that broke out at the secessionist rallies, said he is still haunted by some of the eye-witness accounts.
"I remember interviewing one protester who was shot on his leg and, while [attempting to] run away, fell into gutter and tried to hide himself, and then a particular soldier came to him," Kamara said. The soldier "dragged him out of the gutter and poured acid on him and that man is still recovering from those injuries."
Other witnesses, he added, have reported seeing Nigerian soldiers taking dead bodies to local army barracks.
In one account published by Amnesty researchers, a woman in Onitsha city said her husband called her May 30 to say a soldier had shot him in the stomach and that he was in a military truck with six others, four already dead. He then began whispering that the vehicle had stopped. She heard gunshots, then nothing.
The woman later found her husband's body at a mortuary with three gunshot wounds: one to the stomach and two in the chest, the report said.
Biafra declared independence in 1967 but was absorbed back into Nigeria after a three-year war that claimed an estimated one million lives.
The leader of the current pro-Biafran movement, Nnamdi Kanu, was arrested last year on charges of treason. He is still in custody in the Nigerian capital on orders of President Muhammadu Buhari.
Since Kanu's 2015 arrest, protests have increased seemingly in lockstep with military violence.
Amnesty says President Buhari has promised to investigate but done nothing about previous reports documenting the December 2015 military killings of more than 300 Shiites, and the deaths in military detention of some 8,000 people in the war on Boko Haram's radicals in the north.
Some information for this report was provided by AP.