At least nine Yemeni civilians were killed in air strikes by Saudi-led warplanes that targeted the home of a leader in the dominant Houthi movement in the capital Sanaa, medical sources said on Thursday. The leader, Ibrahim al-Shami, was not in the house at the time.

The air raids by a Saudi-led coalition have intensified in recent weeks as a Gulf Arab ground force and fighters loyal to exiled President Abd-Rabbu Mansour Hadi prepare a campaign to recapture Sanaa, seized by the Houthis in September 2014.

Residents of the Yemeni capital said warplanes made repeated sorties on Yemeni army bases and the vacant homes of relatives of former president Ali Abdullah Saleh, an ally of the Houthis, for several hours on Wednesday night into Thursday morning. The deadliest attacks were in al-Jaraf neighborhood, in northern Sanaa, where warplanes targeted Sham's home. Medical sources said some of the victims fell when residents, including a journalist from the Houthi-run al-Masirah television, gathered at the site.

The coalition began air strikes against the Houthis and their allies, forces loyal to Saleh, in late March after they pushed from their northern stronghold towards the southern port of Aden.