The Nigerian military says bad phone lines prevented soldiers from responding to an attack on a school early Tuesday that killed nearly 60 people.
A spokesman for the Nigerian Joint Task Force, Eli Lazarus, says there were soldiers stationed near the Federal Government College Buni Yadi but because the phones were not working, nobody could reach them.
He says unidentified assailants attacked the school around 2 a.m. Tuesday, setting fire to buildings and killing students as they tried to flee.
There has been no claim of responsibility, but local officials are blaming the radical Islamist sect Boko Haram for the attack.
Lazarus gave an official death toll of 29 but reporters who went to the local mortuary say 59 people were killed. The school is co-educational, but all of those killed were boys.
The governor of Yobe state, Ibrahim Gaidam, toured the ruins of the school on Tuesday and denounced the military's failure to protect the teenaged students.
According to Nigerian newspaper reports, the governor said the soldiers assigned to protect the school had been withdrawn ahead of the attack.
Lazarus says that a military checkpoint about eight kilometers away was recently taken down because of a Joint Task Force operation.
He also said it would not surprise him if the phone lines were deliberately cut ahead of the attack.
Fighters from Boko Haram, whose name means "Western education is a sin," have carried out similar attacks on schools, government facilities and other targets.
The group is blamed for thousands of deaths since launching an uprising against the government in 2009.
In a statement Wednesday, U.N. Secretary-General Ban Ki-moon condemned the killings at the school, adding that "no objective can justify such violence."
Yobe is one of three states where President Goodluck Jonathan declared an emergency last May and launched operations to destroy Boko Haram camps. Despite the efforts, large-scale attacks have continued.
VOA's Hausa Service contributed to this report.