The Mass was to have been held in Serb-controlled Plehane, but organizers canceled the liturgy after their caravan was attacked. UN spokesman Liam McDowall said the Croats were confronted by roadblocks manned by Serbs armed with sticks, clubs, and stones. Plehane is close to Derventa where Cardinal Vinko Puljic of Sarajevo was attacked by a mob on Thursday when he tried to celebrate a Mass there. In Drvar, 80 miles to the west, about 1,500 ethnic Croats rioted the next day over the Serbs' attack on the cardinal.
The violence is a setback for plans to return refugees to their homes from which they were displaced during the 1992-95 war. UN officials said the violence was orchestrated by Serbian and Croatian hardliners who are afraid their power bases will erode if other ethnic groups are allowed to return.