A soldier takes position to stop advancing civil society groups protesting the abduction of Chibok schoolgirls during a rally pressing for the girls' release in Abuja on May 6 ahead of World Economic Forum. (Pius Utomi Ekpei/AFP/Getty Images)

Much of the negative attention being heaped upon Nigeria in the wake of abduction of hundreds of schoolgirls in Chibok has focused on what more authorities could be doing to find the girls.

Now, further information suggests a new line of criticism: What could have been done to prevent the abduction?

Human rights group Amnesty International released a report Friday that says that Nigeria's military headquarters in Maiduguri had four hours' warning of Boko Haram's planned attack on Chibok. Amnesty's account, which it says was reached after "multiple interviews with credible sources," appears to show that the Nigerian military failed to respond to the threat. Local groups first raised the alarm at 7 p.m. on April 14, according to Amnesty, hours before the attack, and local officials reported contacting the military multiple times. Despite this, the nearby military bases of Damboa and Maiduguri did not send extra troops.

Amnesty's account seems to fit in with other independent accounts. The Associated Press' Michelle Faul spoke to one local official who told her that he sent an SOS to army barracks around an hour away about 11 p.m., yet no help arrived. Instead, the 15 or so soldiers stationed in Chibok were reportedly left to fight about 200 militants, the official said, and were forced to retreat after being hopelessly outgunned for over an hour and a half (one soldier reportedly died in the gunfight). It not until close to dawn that the gunmen finally reached the school, Faul reports.

Senior Nigerian military officers have confirmed that they sent no troops despite the warnings, according to Amnesty, with one unnamed official explaining to the organization that "many soldiers are afraid to go to the battle fronts."

The news only compounds the perception that the Nigerian military – and, by extension, President Goodluck Jonathan – have mishandled the kidnapping. Efforts to find and rescue the girls have foundered for more than three weeks, despite the fact that the Defense Ministry had initially said they had rescued all but eight of the girls (they were quickly forced to retract that statement).

For some, the kidnapping is a signal that Nigeria's brutal military reaction to Boko Haram is failing. Amnesty International itself accused Nigeria of committing serious human rights abuses while attempting to crack down on the Islamic extremist group, including the extrajudicial killings of more than 600 people in March.

To confuse matters even further, Boko Haram have reportedly been wearing military uniforms.  “Don’t worry, we're soldiers,” one 16-year-old who escaped the Chibok attack quoted one of the fighters as saying. “Nothing is going to happen to you.”