The leader of Nigeria's Islamist group Boko Haram has defended recent attacks on Christians, and warned of more to come.<br /><br />In a video posted on Youtube, he warned that Nigeria's security forces would not be able to defeat the group.<br /><br />The rise in religious tensions is another headache for President Goodluck Jonathan who's facing a fourth day of nationwide strikes over the rising cost of fuel.<br /><br />Al Jazeera's Haru Mutasa reports from the capital Abuja.
