"The fact that Nigerian security forces knew about Boko Haram's impending raid but failed to take the immediate action needed to stop it will only amplify the national and international outcry at this horrific crime," said Netsanet Belay, Amnesty's Africa director of research and advocacy.
Nigeria's Defence Headquarters spokesman Chris Olukolade dismissed Amnesty's report as baseless and said it was aimed at tarring the reputation of the country's authorities.
"The report is just a collation of the rumors, views and allegations of their fellow detractors and local operatives," he said.
Nigerian President Goodluck Jonathan said on Friday he believed 200 schoolgirls abducted by militants last month in an attack that has stirred global outrage are still in his country and have not been moved to neighboring Cameroon.
Jonathan's government has been criticized for its slow response to the hostage crisis, and Friday is the first time he has said where he thinks the girls are being held.
"There are stories that they have moved them outside of the country. But if they move that number of girls to Cameroon, people will see, so I believe they are still in Nigeria," Jonathan told journalists.
"We are also working with the experts that will use remote sensors to see them (insurgents) wherever they are. So that basically says they are within the Sambisa area," Jonathan said, referring to a forest that is a known Boko Haram hideout near the school from where the girls were abducted.
He was speaking on the sidelines of the World Economic Forum in the Nigerian capital. The event showcased investment opportunities in Africa's biggest economy, but was partially overshadowed by the kidnapping and a broader militant threat.
Militants stormed a secondary school in the village of Chibok, near the Cameroon border, on April 14, and kidnapped the girls, who were taking exams at the time. Fifty have since escaped, but more than 200 remain with the insurgents.
Source: World Bulletin