Nigerian election official said Saturday that Presidential election voting will be extended to Sunday in some areas after several attacks by Boko Haram's miltants and technical problems with the biometric voter's cards. The official added that at least 20 people have been killed in various attacks by Boko Haram militants during the electoral process in Nigeria on Saturday. Boko Haram is a Nigerian Salafist jihadi group, founded in January 2002 by Mohammed Yusuf to apply the Islamic law (Sharia) on all the states of Nigeria. The group which pledged allegiance to the Islamic State (IS) recently has committed several brutal acts against civilians in Nigeria, including the kidnapping of 276 schoolgirls in 2014.