The ruling Socialist Party and Belgrade police turned up the pressure on the opposition on Sunday, warning that their patience was wearing thin and they would crack down hard on any violence or illegal behaviour. Students in the capital responded by sending an open letter to the police that said: "We don't want violence. Words are our only weapon."
Opposition activists suspect that Mr Milosevic is looking for an excuse to break up the daily demonstrations, which represent the most serious challenge to his rule since he took power as Serbia's Communist leader in 1987. Leaders of the Zajedno (Together) coalition of opposition parties say that government provocateurs were responsible for violent incidents last week, when youths smashed windows at the headquarters of the Milosevic- controlled state television and the newspaper Politika. Mr Milosevic, who used tanks to suppress street protests in Belgrade in March 1991, has so far kept his security forces in reserve. Until last Sunday, he appeared to be calculating that his tight control of the media, state administration and security apparatus would eventually cause the demonstrations to fizzle out.
Yet the protests have begun to attract working-class support, a disturbing sign for the authorities. Zoran Djindjic, an opposition leader who has tried to organise trade-union support for strikes to bring down Mr Milosevic, said: "We shall bring the political crisis to boiling point."
A violent crackdown on the opposition would destroy the progress Mr Milosevic had made since 1993 in changing his image abroad from that of bellicose nationalist to supporter of peace in Croatia and Bosnia. Violence would almost certainly rule out the removal of the so-called "outer wall" of international sanctions against Serbia, which include denial of access to the International Monetary Fund and suspension of membership in the Organisation of Security and Co-operation in Europe (OSCE).
Carl Bildt, the Swedish official in charge of civilian aspects of the Dayton peace settlement for Bosnia, said yesterday that Mr Milosevic must refrain from violence against the opposition, since a political crisis in Serbia could spread instability all over former Yugoslavia. "Violence would dramatically increase the distance between the regime in Belgrade and the international community," he added.
The problem for the Serbian opposition is not only to find ways of keeping up pressure on Mr Milosevic but to maintain the unity of Zajedno, a movement that includes liberals, nationalists and ex-nationalists, and a large trade union. Mr Djindjic and another opposition leader, Vuk Draskovic, once embraced a form of strident nationalism that seemed little different from that of Mr Milosevic.
Both men now say they want to follow the example of countries such as Poland and Hungary since 1989 and transform Serbia into a free-market democracy. Mr Djindjic says he supports political pluralism and a law- based state and would respect the Bosnian peace accord.
Even if the opposition fails to topple Mr Milosevic, its leaders believe they have inflicted irreparable damage on his image. "We have torn off his mask ... to show him as he really is - a small-time Balkan dictator," Mr Djindjic said.