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 Nigeria's support for the U.S. bombing of Afghanistan. Obasanjo then visited to urge reconciliation but was booed by residents. Also in October, soldiers had been sent to calm tensions between the Jukun and Tiv communities along the borders between Benue and Taraba states; a Tiv militia then captured and killed them in Zaki-Biam. Obasanjo ordered the army in, where they rounded up and killed as many as 250 to 300 local men. Obasanjo visited the area in 2002 and apologised for the excessive use of force.