BELGRADE, Yugoslavia: For the tenth day in a row, students marched through the streets of Belgrade, protesting the nullification of municipal elections where the opposition party Zajedno won a majority in dozens of towns and cities. More than 50,000 students marched to Belgrade's parliament building, donning gas masks before symbolically spraying the building with detergent and daubing it with slogans like "Red Bandits, Thieves, We Are the Winners." In response to the demonstrations, Serbian President Slobodan Milosevic has shut down one independent radio station and jammed another that was providing favorable coverage of the anti-government protests. The stations struck back by distributing news updates via email and over the Internet. State Department Spokesman Nicholas Burns said Monday that "the United States would be outraged if any attempt was made to use force against the demonstrators," possibly reimposing economic sanctions. Backed by a 80,000-man police force, Milosevic isn't likely to be toppled any time soon. But exactly what concessions Milosevic seems ready to make to stop the demonstrations, or what the opposition will accept, have yet to emerge from Belgrade's chaotic streets.