Clasping his shaking hands, Malam Ahmad inspects the mangled iron beds and blown out walls of a school where dozens of students were massacred last month in north-eastern Nigeria.
"We are still in shock from the horror of the attack," Ahmad said as he guided an Agence France-Presse (AFP) reporter around the now deserted school, where he has taught English since it was established 13 years ago.
Suspected members of Islamist extremist group Boko Haram stormed the secondary school in the farming village of Mamudo on July 6 in the middle of the night, opening fire and throwing explosives inside hostels.
By the time the raid was finished, 41 students and one teacher were dead in yet another attack blamed on the insurgents being pursued by a military offensive.
Local officials say they will not allow the attack to deter them from educating the school's 3 000 students and the military claims the raid was a "desperate move" by insurgents.
The massacre has however instilled deep fear and led to the temporary closure of all schools in Yobe state, where Mamudo is located, to review security.
One student, 17-year-old Bello Sani, said "every night I cry myself to sleep" since the attack. On the night the insurgents arrived, he was sleeping in a classroom that the students transform into a hostel in the evenings.
From school to rubble
"The sounds of guns and explosions woke us up," said Sani, who rode his bicycle to the rubble of the boarding school on the day he spoke to AFP.
"Suddenly we started seeing students running past our class into the bush. We also rushed out of the class and ran with other students into the bush and we kept running until we were deep inside the bush."
He said they remained there until the next day and were eventually found by soldiers.
Another teacher who gave his name as Lawan said students had been asking when the school would reopen.
"It is heart-warming and it boosts our morale as teachers never give in to terror," he said.
Boko Haram, which roughly translates to "Western education is sin", has previously targeted schools as part of its four-year insurgency, but usually not in the same manner.
A rash of school attacks occurred in 2012, but they mostly involved insurgents burning school buildings at night and resulted in relatively few casualties.
A new phase in insurgency
In late June, Yobe state deputy governor Abubakar Aliyu said Boko Haram had burnt 209 schools in the state since November 2011.
The Mamudo incident along with two other deadly school attacks in the region in recent weeks seemed to signal a new phase in the insurgency as soldiers pursue the extremists.
After the Mamudo massacre, Abubakar Shekau, believed to be the leader of Boko Haram's main faction, expressed support for the attack in a video but fell short of claiming he ordered it.
"We know that terrorists want to put us several years back. They will not achieve their objective," said Abdullahi Bego, spokesperson for the Yobe state governor.
Boko Haram's insurgency has left some 3 600 people dead since 2009, including killings by the security forces. The military launched a sweeping military offensive in May aimed at ending the conflict.
In recent weeks, the army has also encouraged the formation of vigilante groups to help flush Boko Haram out of the northeast, where the insurgency has been centred.
While the vigilantes have been credited with helping reduce the number of attacks, some have expressed concern that their activities could spiral out of control and lead to further violence later.
War on youths
In June, Boko Haram issued an audio recording threatening all-out war on youths in the cities of Maiduguri and Damaturu for helping the military.
Over the weekend, suspected Boko Haram members stormed a mosque and shot dead 44 worshippers as well as 12 other people in a nearby village in the north-east.
Those attacks were believed to be in revenge over the formation of the vigilante groups.
A military spokesperson in the north-east accused Boko Haram of resorting to attacking schools to frighten vigilantes as well.
"It is a desperate move, having been weakened following the ongoing military operations which have destroyed their camps and seriously damaged their capabilities," Lieutenant Colonel Sagir Musa said.
Abubakar Mallum, the leader of the vigilantes in Maiduguri, the original home base of Boko Haram, said "we know the school attacks are aimed at rattling us to abandon our holy undertaking of fishing out Boko Haram members".
"It is too late for them because the battle line has been drawn and there is no going back," he said. – AFP