ROUGH CUT ONLY - NO REPORTER NARRATIONbr br Stone-throwing supporters and opponents of Islamist President Mohamed Mursi clashed in the Egyptian city of Alexandria on Friday ahead of a referendum on a new constitution that has divided the Arab world's most populous nation.br br Dozens of activists fought with clubs and swords, witnesses said, and a number of cars were set alight on the streets of Egypt's second biggest city on the eve of a vote that Mursi hopes will bring an end to the country's worsening political crisis.br br Scuffles started near a mosque in Alexandria when opposition members handing out flyers clashed with Mursi supporters.br br The referendum asks Egyptians to accept or reject a basic law that must be in place before national elections can be held early next year - an event many hope can steer the country towards stability.