Violence in Nigeria sparked by fundamentalists demanding more Islamic sharia law has killed at least 80 people. Fighting has now erupted in four Nigerian states, which already implemented sharia law since 2000.The radical group Boko Haram claims links with the Taliban in Afghanistan, and opposes all kinds of Western education. The violence began in Bauchi state, where at least 50 died, and has since spread to Yobe, Kano and Borno in the north-east. The military have imposed a curfew and have taken control of several key roads. There have been scores of arrests. The militants have threatened more attacks. More than 200 ethnic groups generally live peacefully side-by-side in Nigeria, though the introduction of sharia law in some states alienated sizeable Christian minorities, leading to sectarian violence that has killed thousands of people.