Residents of a town in north-east Nigeria are furious at the Nigerian security forces for withdrawing checkpoints ahead of a bloody attack by Islamist militants on a local school.
At least 29 teenage boys died in the raid, blamed on Boko Haram, on a rural boarding school in Yobe state.
Residents say soldiers guarding a nearby checkpoint were mysteriously withdrawn just before the attack.
Another checkpoint on the outskirts of town was also withdrawn a week ago.
The authorities have confirmed 29 deaths, but the AFP news agency has reported 42 dead and other sources have claimed even higher death tolls following the raid on Monday night on the school in Buni Yadi town.
Ibrahim Gaidam, the governor of Yobe state which has a mainly Muslim population, has also criticised the security forces for their extremely slow response.
"It is unfortunate that up to five hours when this massacre took place, there were no security agents around to stop or contain the situation," he said in a statement.
The attackers reportedly hurled explosives into student residential buildings, sprayed gunfire into rooms and hacked a number of students at the secondary school to death.
"Some of the students' bodies were burned to ashes," Police Commissioner Sanusi Rufai said of the raid on the Federal Government College of Buni Yadi.
Most of the school was burned to the ground and at least 11 students were seriously injured.
All the victims were boys - female students were told to go home, get married and abandon education, said teachers at the school.
Boko Haram, whose name means "Western education is sin", has attacked dozens of schools in north-east Nigeria, since it began it began its bloody fight for an Islamic state in the north of the country in 2009.
The group has not claimed responsibility for the attack.
Last September, 40 students were killed at an agricultural college during another night-time raid, and 300 people have been killed this month alone in attacks blamed on it.
Nigeria's military said on Tuesday it was pursuing the attackers.
"We assure all law-abiding citizens that we will continue to do what is necessary to protect lives and property," a statement said.
President Goodluck Jonathan condemned the killings as "heinous, brutal and mindless", labelling the perpetrators "deranged terrorists and fanatics who have clearly lost all human morality and [who have] descended to bestiality".
The BBC's Isa Sanusi, from the Hausa service, says Boko Haram tends to attack schools in the mainly Muslim north that teach Nigeria's national curriculum, which the militants consider to be Western.
Mr Jonathan declared a state of emergency in Yobe and two other northern states in May in an attempt to quell the insurgency.
He has defended the army's record, saying the militants have been confined to a small area near the border with Cameroon.