CAIRO - Fighting broke out in central Cairo on Friday evening between supporters and opponents of ousted President Mohamed Morsi, witnesses said.A group of Islamist supporters of Morsi gathered outside the national broadcasting headquarters on the banks of the Nile, about a kilometer (half a mile) from Tahrir Square, where Morsi's liberal opponents have set up camp.Television images showed groups of youths running. Some threw fireworks which landed among groups of rival protesters.