Nigeria Had 4-Hour Warning on School Raid, Amnesty International Says Amnesty Int'l cites “gross dereliction of Nigeria’s duty to protect civilians."

ABUJA, Nigeria, May 9, 2014 -- Nigerian authorities failed to act on warnings about Boko Haram’s imminent raid on a boarding school where it abducted more than 240 girls last month, according to Amnesty international.

The London-based human rights group, after verifying the information with “credible sources,” said Nigerian security forces knew of the attack four hours before Boko Haram struck.

“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,” Netsanet Belay, Amnesty International’s Africa director, research and advocacy, said today in a statement.

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“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.”

Among the locals who sounded the alarm, civilian patrols set up by the military in a neighboring village triggered a chain of phone calls the evening of April 14 after they noticed unidentified armed men on motorbikes heading toward Chibok, where the schoolgirls were later abducted, according to sources Amnesty International has interviewed.

The human rights group says that two senior officials in Nigeria's armed forces have confirmed the military's being aware of the planned attack, including one who said an overextended commander was unable to mobilize reinforcements.

Nigerian Finance Minister Ngozi Okonjo Ewayala -- after blurting out that "I'm tired of the same story -- said here today that she was unable to comment on the Amnesty International accusations, explaining, "I’m the minister of finance. I can only tell you the full commitment of this government to fight. And the pledge of the international community as demonstrated by this conference,” referring to the World Economic Forum (WEF) conference in Nigeria this week.

Ewayala, a former foreign minister, added, “The government is doing everything. The government has sent additional troops. The government is doing aerial surveillance. The government is working with companies that have satellite. The government is working with the U.S., is waiting for the promised help from all the sources that have pledged."

The Nigerian Embassy in Washington and the Nigerian U.N. Mission in New York City have not responded to ABC News' repeated requests for comment.

U.S. State Department spokeswoman Jen Psaki, when asked about the Amnesty International allegations at a briefing today, said, "Obviously, given how horrific this tragedy is of the kidnapping of these girls, I think it’s only natural that people are looking back and seeing what could have been done differently. ... We’ve been working closely with the Nigerian government for months if not years and assessing their ability to deal with these threats.

“I don’t have any assessment from here, from the U.S. government, of past reports.”

As for U.S. assistance, there are at least 26 U.S. officials specifically tasked to the Boko Haram kidnapping for the moment, according to the Defense and State Departments, including 18 military personnel, four State Department officials and three FBI officials, some of whom are in transit.

Meanwhile, a peace negotiator used in previous formal negotiations with Boko Haram – the group responsible for kidnapping hundreds of school girls – has proposed a formal negotiation process to the Nigerian government that he hopes will allow for the girls’ safe return.

The operation could be convened quickly, with the girls returned, alive, within a week, Shehu Sani told ABC News.

The negotiating team should involve a committee of Islamic clerics from the north-eastern region of the country, along with insurgents who are in prison, he said. Sani said he believes Boko Haram will be willing to return the girls in exchange for their members who have been incarcerated.

Boko Haram’s threats to “sell” the girls into slavery is a positive signal because, normally, they vow to “kill” their captives, he added.

“Hope is not lost, as long as these girls are alive,” he said.

The peace negotiator, who has previously traveled to Maiduguri in Borno State, in northeastern Nigeria, for direct talks with Boko Haram leadership in a burned-out mosque, is concerned that international attention is forcing Nigeria’s government to take a hardline but miscalculated approach.

"This government is helpless and hopeless on solving the problem” he said. “The most important thing is to get them back alive, and you cannot do that through force.”

Instead of convening a negotiating mission, the Nigerian government has appointed a committee led by military and intelligence chiefs, to whom Boko Haram will be unwilling to talk, Sani said.

He cited recent examples of armed raids, attempting to rescue foreign hostages, that have resulted in the death of captives.

“The government of Nigeria is pretending to be serious simply because the world is taking an interest,” he said.

ABC News' Ali Weinberg and Luis Martinez contributed to this report.