MAIDUGURI, Nigeria (AP) - The leader of Nigeria's Islamic extremist group Boko Haram has denied agreeing to any cease-fire with the government and said more than 200 kidnapped schoolgirls all have converted to Islam and been married off. In a new video released late Friday night, Abubakar Shekau dashed hopes for a prisoner exchange to get the girls released. "The issue of the girls is long forgotten because I have long ago married them off," he said, laughing. "In this war, there is no going back," he said in the video received by The Associated Press in the same way as previous messages. Nigeria's chief of defense staff, Air Chief Marshal Alex Badeh, on Oct. 17 announced that Boko Haram had agreed to an immediate cease-fire to end a five-year insurgency that has killed thousands of people and driven hundreds of thousands from their homes in northeast Nigeria. But attacks and abductions have continued with the extremists this week seizing Mubi, a town of more than 200,000 people. Fighting also continued Friday in Vimtin, the nearby village where Badeh was born. Shekau in August announced that Boko Haram wanted to establish an Islamic caliphate, along the lines of the IS group in Syria and Iraq, and fleeing residents have reported that hundreds of people are being detained for infractions of the extremists' version of strict Shariah law in several towns and villages under their control. Boko Haram's kidnapping of 276 schoolgirls writing exams at a boarding school in the remote northeastern town of Chibok in April prompted an international campaign for their release and criticism of Nigeria's government for not acting quickly to free them. Dozens of the girls escaped on their own in the first couple of days, but 219 remain missing. Faul reported from Johannesburg.