A Syrian government warplane has crashed in a built-up area of the north-western town of Ariha, killing 12 people, activists say, reports BBC.The UK-based Syrian Observatory for Human Rights activist group said the crash occurred amid bombing raids.Ariha was one of the last government strongholds in Idlib when it was captured by rebels in May.The fall of the Ariha left most of Idlib province, bordering Turkey, in rebel hands.