SARAJEVO: Holbrooke has his hands full, with tensions between Serbs and Muslims escalating rapidly. The Serb army refuses to conduct high level talks with NATO officers while Bosnian Muslims detain Serb officers. "We will not tolerate the kind of threats coming out of the Bosnian Serbs," Holbrooke told reporters at a stop in Budapest, Hungary. Violence is growing in Sarajevo with both Serbs and Muslims reporting attacks. Four Muslim truck drivers were allegedly beaten by armed Serbs, according to hospital officials. SRNA, the Bosnian Serb news agency, claimed a Serb had been beaten by Muslims in the Bosnian Muslim section of Sarajevo. While Admiral Leighton Smith has played down the seriousness of the growing disarray, the situation clearly is deteriorating fast.