Yemen’s Houthi insurgents have shut down six radio stations in the capital Sanaa, the journalists’ union said, with reporters saying the move came after broadcasters refused to air rebel propaganda. The Iran-backed Houthis seized Sanaa from the internationally recognised government in 2014, sparking a civil war that has devastated the already impoverished country. On Saturday, the syndicate of journalists quoted a statement from the Voice of Yemen radio saying Houthis closed the station. “Security forces from the de facto authorities in Sanaa stormed the radio station on Tuesday and closed it,…