The death toll has risen to 59 from Tuesday's attack by militants on a school in northeastern Nigeria.
Reporters at the scene say more bodies from the assault on the Federal Government College of Buni Yadi have been found and brought to the local mortuary.
The governor of Yobe state, Ibrahim Gaidam, toured the ruins of the school on Tuesday and denounced the military's failure to protect the teenage students.
Shortly before the attack, the governor said, the few soldiers assigned to protect the school were withdrawn for no apparent reason.
There has been no claim of responsibility, but local officials are blaming the radical Islamist sect Boko Haram for 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.
In a statement Wednesday, U.N. Secretary-General Ban Ki-moon condemned the killings, adding that "no objective can justify such violence."
Witnesses to the attack said dozens of gunmen moved in around 2 a.m. Tuesday, setting buildings on fire and killing students with machetes and knives.
The school is co-educational, but all of those killed were boys.
Boko Haram has said it wants to turn Muslim-majority northern Nigeria into an Islamic state. The group is blamed for thousands of deaths since launching an uprising against the government in 2009.
Yobe is one of three states where President Goodluck Jonathan declared a state of emergency last May and launched operations to destroy Boko Haram camps. Despite the efforts, large-scale attacks have continued.
Some information for this report comes from AP and Reuters.