Protesters blocked a highway outside the northwest Nigerian city of Kaduna on Monday to demand the release of kidnapped students.
Several dozen protesters barricaded the road outside the Federal College of Forestry Mechanisation on the city's outskirts, disrupting traffic, an AFP journalist saw.
Gunmen are still holding 39 college students who were seized from hostels in a raid on March 11. The military rescued 180 other students and staff.
The protestors carried placards with inscriptions such as "Bring back our children" and "Is it a crime to seek education?"
They pushed a tractor belonging to the college along the highway to symbolize the closure of academic activities at the school.
Wailing mothers holding posters of their children sat on the highway and pleaded for their rescue.
"We beg on you, God, to have mercy and help rescue our children, touch the hearts of their captors," one mother clad in black, shouted with both hands raised in supplication.
Kambai Sam, head of an association of the parents of kidnapped students, criticised the government's handling of the hostages.
"We have put our trust in the government and school authority to rescue the students in good time and safely, but that has not happened," he said.
Gangs in northwest and central Nigeria, who are known locally as bandits, have recently turned their focus to mass kidnappings, seizing school students for ransom.
At least five mass kidnappings have occurred since December.