Farmers march past Zappeion Hall in central Athens yesterday, during one of five demonstrations that sowed utter chaos for hours in the capital. The other demonstrations involved university professors, students and striking garbage collectors. About 7,000 farmers from central Greece came to press their demands for higher subsidies and compensation for damaged crops. 'We are here for a day in order not to come here forever,' one slogan said. Police used tear gas when they tried to break through a cordon near the office of the prime minister, who is on an official visit to Japan.