Confused students, some as young as 11, thought the militants were soldiers trying to help them, and many scrambled to get inside the trucks. Residents reported hearing the captured girls scream as the trucks sped away.
Amnesty said police officers in the town had fled because they feared they would be overpowered. The police in Dapchi could not immediately be reached for comment.
“The Nigerian authorities must investigate the inexcusable security lapses that allowed this abduction to take place without any tangible attempt to prevent it,” Osai Ojigho, Nigeria director of Amnesty International, said in the news release.
“As an even greater priority, the government must use all lawful means at its disposal to ensure that these girls are rescued,” she added.
The military spokesman, Gen. John Agim, said the rights group should have reported its concerns to a committee set up to investigate the kidnapping.
Six weeks before the attack, the military abandoned a checkpoint at the entrance to Dapchi after soldiers were redeployed to fight Boko Haram near the border with Niger. The town had not had security issues in the months before the attack.
General Agim noted that the United States was in the process of selling fighter jets and weapons to help Nigeria fight the war with Boko Haram, and said that Amnesty’s aim was “to see how they can scuttle those efforts and U.S. help to Nigeria.”
American military officials have said that Nigerian officials have requested intelligence assistance to find the girls, who are believed to have been kidnapped by a faction of Boko Haram affiliated with the Islamic State.
Amnesty has released numerous reports critical of the Nigerian military, alleging actions such as the unlawful detention of civilians. The military has a record of abuse, including indiscriminate massacres, in its hunt for Boko Haram members.
Amnesty said its researchers had visited Dapchi and interviewed 23 people, including girls who escaped, parents of abducted girls, local officials, witnesses and three security officials. The rights group said it shared its findings with Nigerian officials two weeks ago.
On the afternoon of the kidnappings, an initial call was made to the army command in Geidam, about 30 miles from Dapchi, informing soldiers that Boko Haram fighters had been spotted outside Geidam. Calls were later made to the command, with the answering officer responding that the military was aware of the situation, Amnesty said.
“However, the evidence documented by Amnesty International shows that the military did nothing to engage with Boko Haram and ensure the protection of civilians,” the report said.
Later in the afternoon, Boko Haram fighters arrived in Gumsa, a town close to Dapchi, and stayed there two hours. Residents of Gumsa called friends in Dapchi to warn them that fighters were on the way.
“One villager who received such a call said he informed a police sergeant who promised to notify the Dapchi division police officer,” Amnesty said.
The group’s researchers learned that police officers had run away because they believed they would be no match for the Boko Haram fighters. Residents said the nearly 50 militants had at least one truck mounted with a high-powered weapon.
In Dapchi, residents said militants had passed the police station on their way in and out of town. At least two people said their friends had told them that they had called the police after seeing militants arrive, but that they had received no response.
Residents said the police chief was out of town the night of the attack.
Babale Abubakar, a government worker in Dapchi, said he thought it unlikely that residents would call the military, “because people do not readily just call them like that, but they will call their police or inform officers that they see in the town or other security agents.”
In April 2014, Boko Haram militants stormed a school in the village of Chibok, kidnapping nearly 300 students. More than 50 girls escaped the night of that attack. The government negotiated the release of about 100 of them last year, and several have escaped. About 100 others are still being held by militants.
The Nigerian government has come under fire for allowing another similar kidnapping to happen again.
“The Nigerian authorities have failed in their duty to protect civilians, just as they did in Chibok four years ago,” the Amnesty news release said.
Nigerian officials said on Monday they had deployed at least 2,000 armed police officers to more than 300 schools as part of an effort to bolster security in northeastern Nigeria, where Boko Haram is concentrated.