Jos and Biu Attacks in Nigeria Target Christians JOS, Nigeria (AP) - A car bomber detonated his explosives on Sunday outside a church in this central Nigerian city, and gunmen attacked another church in the nation's northeast, killing at least four people and wounding dozens in the latest attacks against Christian worshipers, officials and witnesses said. While no group immediately claimed responsibility for the attacks in Jos and Biu, a city in the northeastern state of Borno, they bore the hallmarks of assaults by a radical Islamist sect known as Boko Haram, which continue unabated despite a heavy military presence in the region. In Jos, a city on the uneasy dividing line between Nigeria's largely Muslim north and its Christian south, the bomber drove toward the compound of the Evangelical Church Winning All chapel and detonated his explosives nearby, said Abu Emmanuel, a spokesman for Plateau State police. The shock wave from the blast collapsed a portion of the building, causing injuries inside, Mr. Emmanuel said. Angry youths later surrounded the area, striking back against Muslims in retaliatory violence, witnesses said. Four people and the bomber were killed, while more than 40 were wounded, Mr. Emmanuel said. In Biu, gunmen opened fire on Sunday during a service at a church, witnesses said. An usher and another worshiper were killed and others were wounded, said a military spokesman, Col. Victor Ebhaleme. The Borno State police commissioner, Bala Hassan, confirmed the attack and said officers were investigating. Churches across the country now receive additional military and police protection. In Jos, a city in the fertile central belt, religious rioting and violence has killed thousands in the past decade. But the attacks are often rooted in political and economic disputes among the ethnic groups living in the region.