'Please find them': Parents of Kaduna abductees plead for their return

Distraught parents protested outside the secondary school in northwestern Nigeria's Kaduna state, as they demanded the return of several dozens students seized in a kidnapping early Sunday.

Gunmen abducted 140 students after forcing their way into Bethel Secondary School, as a spate of kidnappings for ransom engulf central and northern Nigeria.

"We will continue to talk, we will make noise. We call on the international community, we call on every person that is involved or that is responsible in any way that can eliminate our problems, to come to our aid. We do not have help anymore. Please, they should come to our aid," said Mustapha Kumbe, father of a student who was abducted

Criminal gangs have raided villages in northern and central Nigeria, stealing livestock and grabbing travelers on highways in recent weeks. 

Kaduna state authorities said special police units had been sent to hunt the kidnappers.

"Tactical police teams went after the kidnappers," said the state's police spokesman Muhammed Jalige

"We are still on the rescue mission."

President Muhammadu Buhari has come under heavy criticism for his worsening security record. 

Armed violence in the northeast and southeast, as wells as kidnappings in the north and central regions have prompted calls for Buhari to resign, criticism that the Nigerian government has dismissed.