(SANAA, Yemen) — Strikes killed more than 30 civilians in a mountainous northern Yemeni province Saturday, the U.N. humanitarian chief for the country said, calling the attack “shocking.” The Yemeni rebels, known as Houthis, accused the Saudi-led coalition of launching retaliatory airstrikes, after they shot down a coalition warplane over the province of Jawf. Saudi Arabia’s state-run news agency quoted Col.