KANO, Nigeria- Bomb blasts have rocked northeastern Nigerian cities under a state of emergency as an ultimatum from Islamists for Christians living in the area to leave expired, officials said Thursday. No casualties were reported after the attacks in Maiduguri and Damaturu late Wednesday, claimed by the same purported spokesman for Islamist group Boko Haram who on Sunday issued a three-day ultimatum for Christians living in Nigeria's mainly Muslim north to leave. One of the bombs in Maiduguri, Boko Haram's stronghold, destroyed a house near a customs barracks, according to a customs source and resident. The Damaturu blast occurred at an open-air pub.