Thousands of mourners defied South African police to bury two African National Congress activists in a funeral that turned violent after more than four hours of tense confrontation. Police tolerated open defiance of orders forbidding political statements and banners at the funeral for black student activists Coline Williams, 22, and Robbie Waterwitch, 20. But the Rev. Richard O'Rourke said police used dozens of canisters of tear gas to break up the traditional post-funeral meal attended by about 500 people at St. Matthew's Catholic Church in Bonteheuvel, a mixed-race area outside Cape Town. Williams and Waterwitch died July 23 when a bomb they were handling exploded.