YAOUNDE, Cameroon — Armed separatists have kidnapped at least 78 students and their principal from a Presbyterian school in Nkwen village in Cameroon's restive northwest region, a governor said Monday.

The kidnapping late Sunday took place near Bamenda, the capital of the troubled English-speaking region, according to Governor Deben Tchoffo.

A video purportedly of the kidnapped children has been released on social media via men who call themselves "Amba boys," a reference to the state of Ambazonia that armed separatists are trying to establish in Cameroon's Anglophone northwest and southwest regions.

In the video, the kidnappers force several young male students to give their names and the names of their parents. The children say they were kidnapped late Sunday by the armed men and they don't know where they are being held.

The men who identify themselves on the video as the kidnappers say they will only release the children when they achieve what they want.

"We shall only release you after the struggle. You will be going to school now here," say the men. The video could not be independently verified, but parents have said on social media that they recognize their children in the video.

In a statement on Monday, Amnesty International Deputy Regional Director for West and Central Africa Samira Daoud called the abduction "appalling" and said they exemplify the price the general public is paying as violence escalates in the region.

"The abduction of schoolchildren and teachers can never be justified. Whoever is responsible must release and return the victims immediately," Daoud said.

She added: “We express solidarity with the families of these children and demand that the Cameroon authorities do everything in their power to ensure all the pupils and school staff are freed unharmed. In a case with a chilling echo of the 2014 kidnappings of the Chibok schoolgirls in Nigeria, it is vital that Cameroon’s government act swiftly and decisively to reunite these children with their loved ones."

Hundreds have been killed in Cameroon's Anglophone regions in the past year, where violence between armed separatists and the military has increased since a government crackdown against protesters in the northwest and southwest regions. The demonstrators claim that as the English-speaking minority they are marginalized by the French-speaking government.

Violent separatists have since taken up arms to destabilize the Anglophone regions to win independence for the areas they want to declare a separate state, which they call Ambazonia. They have mounted attacks against civilians who do not support their cause.

There have been other kidnappings from schools in the region, but this is the largest number kidnapped at once. Armed separatists have even killed teachers who defied instructions to keep schools closed. They have torched at least a hundred schools and chased students and teachers from schools which they then take over as training grounds.

Last week separatist militants attacked workers on a state-run rubber plantation in southwestern Cameroon, chopping off their fingers because the men had defied an order to stay away from the farms.

An American missionary also died in the northwest region around Bamenda when he was shot in the head amid fighting between armed separatists and soldiers.

The turmoil in Cameroon comes as President Paul Biya, who has led since 1982, easily won a seventh term last month in an election that the United States says was marked by irregularities. The government did away with presidential term limits several years ago, part of a trend in Africa that has dismayed many. Biya will be inaugurated Tuesday, and many opposition supporters have said they will continue demonstrations until he leaves power.