TUZLA: Among the other complex issues confronting Christopher in Bosnia will be what to do about thousands of missing Muslims. Though U.N. investigators began digging today at the site of a mass grave near the northern Bosnian town of Jajce, even Admiral Leighton Smith, commander of NATO operations in Bosnia, estimates that there may be as many as 300 such graves scattered across the war zone. Also, TIME's Alexandra Stiglmayer reports that Srebenican women demonstrated again in Tuzla on Friday. "It was quite violent," says Stiglmayer. "They threw rocks and broke windows of a government building." Dozens of the women, who are the wives and daughters and mothers of men missing since the Serbs overran the Muslim enclave of Srebenica last fall, also traveled to Sarajevo to protest what they claim is the inaction of the government in getting an accounting. "These women claim that out of 8,000 missing men, 3,000 are still alive and being held in Serb prisons or labor camps," says Stiglmayer. "While the 3,000 number seems very high, I have heard many stories that would suggest that several hundred of these men may still be held. But the women are protesting the official inaction on the issue. And they are right because no one has tried to find these people."