Heavily equipped riot police in central Athens yesterday blocked protesting firefighters who tried to enter Parliament in their quest to obtain better pay and work conditions. Minor scuffles broke out between the two as police used tear gas to break up the 1,500 demonstrators. One of the protesters was treated for breathing problems. The city’s central streets were blocked off at around 1.30 p.m. because of the gathering, causing serious traffic problems. The protest was organized by a union which represents about 5,500 firemen on short-term contracts.