The human rights group accused the authorities of “gross dereliction of duty”, saying security forces knew of the Boko Haram raid in the north-eastern state of Borno almost four hours before it took place – but did too little to stop it.
However, intelligence services claimed that they had discovered the location of the gunmen and at least some of the missing girls, who are understood to have been split into groups. President Goodluck Jonathan said earlier that he believed the missing girls were still in Nigeria.
The “damning” claim that warnings failed to galvanise the military into preventing the abductions was made as the US-based organisation released details of information from its “multiple interviews with credible sources”.
Read more: What is Boko Haram?Netsanet Belay, Amnesty’s director for Africa, said: “The fact that Nigerian security forces knew about Boko Haram’s impending raid, but failed to take [immediate steps] to stop it, will only amplify the national and international outcry at this horrific crime.
“It amounts to a gross dereliction of Nigeria’s duty to protect civilians, who remain sitting ducks for such attacks. The Nigerian leadership must now use all lawful means at their disposal to secure the girls’ safe release and ensure nothing like this can happen again.”
At 11.45pm on 14 April, 200 armed men from the militant Islamic group Boko Haram entered the town of Chibok where, after a brief gun battle with police and soldiers, they seized 276 pupils from the Government Girls Secondary School. Fifty have since escaped, but the rest remain with the insurgents.
Amnesty said the military was told of the impending attack as early as 7pm. Warnings were repeated through the evening but reinforcements failed to reach the town until the next day, long after the raid and the abductions.
Amnesty said: “An inability to muster troops – due to poor resources and a reported fear of engaging with the often better-equipped armed groups – meant that reinforcements were not deployed to Chibok that night.”
Civilian patrols in the nearby village of Gagilam were said to be among the first to report the presence of a large group of unidentified armed men on motorcycles. Among those alerted, according to Amnesty, was the Borno state governor. Herdsmen had even reported that the armed men had demanded directions to the secondary school.
An official who was contacted by residents of Gagilam reportedly told Amnesty: “I was promised by the security people that reinforcements were on their way.”
Nigerian officials said they “doubt the veracity” of the Amnesty report. “If the government was aware [beforehand] there would have been an intervention [against the militants],” the Information Minister, Labaran Maku, told BBC World TV. However, he said the government would investigate the claims.
As British experts arrived to help in the search, David Cameron said: “[This kidnapping] is … an act of pure evil.”
Saudi Arabia’s leading religious authority, Grand Mufti Sheikh Abdulaziz al-Sheikh, condemned Boko Haram as a group “set up to smear the image of Islam” and also condemned the kidnapping.