(Reuters) - A sewage backup caused a big stink at the United Nations on Tuesday, forcing diplomats and their staff to evacuate the Security Council and General Assembly. Spokesman Farhan Haq said the evacuation was a precautionary measure after a strange smell was noticed in parts of the U.N. secretariat building. He said the odor was due to sewage backup possibly caused by high tides in the nearby East River. "There were gases released from the sewage but they're not harmful," Haq said. Firefighters and hazardous materials experts had been called to the scene. U.N. management officials were working to...