Yemen's separatist movement on Friday announced a constitution for an independent nation in the south and demanded other factions in the war-torn country accept the move in an escalation of a confrontation that has pitted Gulf powerhouses Saudi Arabia and the United Arab Emirates against each other. The UAE-backed Southern Transitional Council depicted the announcement as a declaration of independence for the south. But it was not immediately clear if the move could be implemented or was largely symbolic. Last month, STC-linked fighters seized control of two southern provinces from Saudi-backed forces and took over the Presidential Palace in the south's main city, Aden. Members of the internationally recognized government which had been based in Aden fled to the Saudi-capital Riyadh. On Friday, Saudi warplanes bombed camps and military positions held by the STC in Hadramout province as Saudi-backed fighters tried to seize the facilities, a separatist official said. It was the late