Parents have converged on a secondary school in Nigeria's north-western Katsina state, begging authorities to save hundreds of boys abducted by gunmen.
More than 300 students taken on Friday night from the all-boys Government Science school in Kankara remained missing on Sunday.
"We will not rest until we see the end of this," state spokesman Abdul Labaran said.
Mr Labaran added that military and intelligence chiefs were in Kankara to lead the rescue.
While 321 students were missing, he said some could have gone home to other states.
All state schools in Katsina were ordered to close because officials did not know the attackers' motives, the education commissioner said.
Many Nigerians including television producer and actor Debo Macaroni expressed outrage at the mass abduction laying responsibility at the feet of the President.
Abubakar Lawal came from Zaria, a city 120 kilometres south of Kankara. Two of his three sons at the school were among the missing.
"From yesterday I was here, praying that the almighty Allah should rescue our people," he said outside the dusty school grounds.
One of his missing sons, 17-year-old Buhari, was named after President Muhammadu Buhari, a native of Katsina state.
Yahaya, 17, told Reuters he escaped on Saturday. He gave only one name for fear of reprisals. He said he sneaked away while the kidnappers transferred students to different locations in the forest.
Parents demanding the return of their children who were kidnapped by gunmen in Kankara. Source: sunnewsonline.com
"We met someone with motorcycle who brought us to a nearby village," He said. "From there someone brought us to Kankara."
He said group leaders told the men not to harm them.
Attacks by armed gangs, widely known as bandits, are common throughout north-western Nigeria.
The groups attack civilians, stealing or kidnapping them for ransom. Islamist militants are more common in the northeast.
There is growing anger with the precarious security situation in Nigeria, Africa's most populous nation.
Late last month, Islamist militants killed scores of farmers in north-eastern Borno, beheading some of them.
