Abdullahi Bego, special adviser to the Yobe state government, told the BBC Monday there were no security forces at the College of Agriculture in Gujba when the attack took place early Sunday.
Security forces were supposed to regularly patrol the school, he said.
An unknown number of gunmen stormed a dorm where students were sleeping, killing 50 and injuring 18.
Boko Haram was suspected. The militant group, which carried out a similar attack that killed 29 students and a teacher at a high school dormitory in July, had not claimed responsibility for the latest attack.
The Islamic group attacks schools because it regards them as a symbol of Western culture, the BBC said. Boko Haram, in effect, means "non-Islamic" education is a sin.
Bego said schools in the region wouldn't be closed due to Sunday's shooting because that's what the "terrorists" wanted.
"We are committed to providing education to our children in Yobe state and in northeastern Nigeria," he said.