 Complete the following phrase:  In 2000, Obasanjo banned the Oodua Peoples Congress OPC, a Yoruba nationalist group involved in violence against other ethnicities, and ordered the arrest of its leaders. In September 2001, violence between indigenous Christians and northern Muslim traders in Plateau State resulted in around 500 deaths before the army moved in and regained control. Obasanjo then visited and urged reconciliation. In October 2001, Muslim demonstrators in Kano killed around 200 Igbo in response to Nigerias support for the 