More than 100 girls were missing in Nigeria on Wednesday in wake of a Boko Haram attack on their school in northeast Nigeria. Extremist militants stormed the Government Girls Science Secondary School in Dapchi, Yobe state, on Monday evening. Locals initially said the girls and their teachers fled. Fears have been growing about the whereabouts of the students. Their disappearance, if confirmed, would be one of the largest since Boko Haram abducted more than 270 schoolgirls from the town of Chibok in 2014. That case drew global attention to the nine-year insurgency, which has sparked what the United Nations has called one of the worlds worst humanitarian crises. President Muhammadu Buhari dispatched his foreign and defense ministers on Wednesday to Yobe to investigate the situation, said Information Minister Lai Mohammed, who was also headed there. But he declined to confirm whether any of the students was missing. Around 50 parents and guardians converged on the school on Wednesday to demand answers, as police said 111 were still missing. "I saw girls crying and wailing in three Tata vehicles and they were crying for help," said a witness from the nearby village of Gumsa who was reportedly forced to show the insurgents the way out of the area and then released. The police commissioner of Yobe state, Abdulmaliki Sumonu told reporters in the state capital, Damaturu, that "815 students returned to the school and were visibly seen, out of 926 in the school". "The rest are missing. No case of abduction has so far been established," he added. Abubakar Shehu, whose niece is among those missing from Dapchi, told AFP: "Our girls have been missing for two days and we dont know their whereabouts. "Although we were told they had run to some villages, we have been to all these villages mentioned without any luck. We are beginning to harbor fears the worst might have happened. "We have the fear that we are dealing with another Chibok scenario." The state-run boarding school in Dapchi caters for girls aged 11 and above from across Yobe state, which is one of three worst affected by the insurgency. Inuwa Mohammed, whose 16-year-old daughter, Falmata, is also missing, said it was a confused picture and that parents had been frantically searching surrounding villages. "Nobody is telling us anything officially," he said. "We still dont know how many of our daughters were recovered and how many are still missing. "We have been hearing many numbers, between 67 and 94." Yobes education commissioner, Mohammed Lamin, said the school had been shut and a rollcall of all the girls who have returned was being conducted. "It is only after the head-count that we will be able to say whether any girls were taken," he said. Some of the girls had fled to villages up to 30 kilometers (nearly 20 miles) away through the remote bushland, he added. Boko Haram has seized thousands of women and young girls, as well as men and boys of fighting age during the conflict, which has left at least 20,000 dead since 2009. Some 300 children were among 500 people abducted from the town of Damasak in November 2014. Getting accurate information from the remote northeast remains difficult. The army still largely controls access and infrastructure has been devastated by nine years of conflict. In Chibok, the military initially claimed the students had all been found but was forced to backtrack when parents and the school principal said otherwise. Of around 270 girls originally abducted from their school in Chibok in 2014, about 60 escaped soon afterwards and others have since been released after mediation. Around 100 are still believed to be in captivity. Last month, the group released a video purporting to show some of the Chibok girls still in its custody, saying they do not wish to return home. As the issue gained world attention, spawning the hashtag #BringBackOurGirls, the then president Goodluck Jonathan was increasingly criticized for his lackluster response. The mass abduction and Jonathans handling of it was seen as contributing to his 2015 election defeat to Muhammadu Buhari, who promised to bring the Boko Haram insurgency to an end. But despite Buharis repeated claims the group is weakened to the point of defeat, civilians remain vulnerable to suicide attacks and hit-and-run raids in the remote northeast.