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 on Monday.The kidnapping late on 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 northwest and southwest regions.In the video, the kidnappers force several of the young male students to give their names and the names of their parents. The children say they were kidnapped late on Sunday by the Amba boys, and they don't know where they are being held.The men who identify themselves 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 who identified themselves as Amba boys. While the video could not be independently verified, parents have been reacting on social media saying they recognise their children in the video.Hundreds have been killed in Cameroon's Anglophone regions in the past year, where violence between armed separatists and the military have increased since a government crackdown against protesters in the northwest and southwest regions who claim that as the English-speaking minority they are marginalised by the French-speaking government.Violent separatists took up arms to destabilise the Anglophone regions to win independence for the areas they want to declare a separate state, which they call Ambazonia.Last week separatist militants attacked workers on a state-run rubber plantation in restive 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 after he was shot in the head amid fighting between armed separatists and soldiers in northwestern Cameroon.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.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.