Rebels unleashed an unprecedented barrage of mortar fire against troops in Aleppo after announcing a "decisive" battle for Syria's second city, residents and a watchdog say. Shells crashed down at a steady rate and clashes were widespread, leaving layers of dust and smoke over Aleppo, according to the residents and the Syrian Observatory for Human Rights. "The fighting is unprecedented and has not stopped since Thursday. The clashes used to be limited to one or two blocks of a district, but now the fighting is on several fronts," the Observatory's Rami Abdel Rahman said. Residents of neighbourhoods previously spared the worst of the two-month-old battle for Aleppo also said the violence was "unprecedented". "The sound from the fighting... has been non-stop," said a resident of the central district of Sulimaniyeh, who identified himself only as Ziad. "Everyone is terrified. I have never heard anything like this before."
