Sanaa, September 22 Warplanes from a Saudi-led alliance bombed two houses in Yemen’s capital today, killing at least 20 people, medics and local officials said. The attack came a day after similar air strikes killed around 50 people and as Gulf Arab ground forces seek to advance against the Houthi fighters who hold the capital, Sanaa. “Two missiles hit the two houses in the Asbahi district in southern Sanaa, destroying them, killing 20 people and wounding others,” a medic at the scene said. A local official had earlier said that a hotel in the same district had been hit. An alliance of Arab states - mostly the wealthy neighbours of impoverished Yemen on the Arabian Peninsula - intervened in the country’s civil war in late March to restore President Abd-Rabbu Mansour Hadi after the Houthis pushed him into exile. Gulf ground troops are now trying to push into Houthi strongholds in northern Yemen and in Sanaa, which the group seized a year ago. So far, they appear to have made few gains. Saba, the Houthi-controlled state news agency, said 236 people have been killed in air strikes over the last four days. Medics reached by Reuters estimated the death toll was lower for some of the incidents mentioned in the report.