A wave of Houthi attacks Tuesday on Saudi Arabia wounded more than 70 people and ignited fires at several oil facilities and utilities in the kingdom’s southern region, authorities said, a major escalation in the renewed conflict between an important US ally and the Iranian-backed rebels in Yemen. The attacks come after weeks of escalating clashes between the Houthis and Saudi-backed government forces in Yemen, which shattered a four-year truce in the country’s civil war. Fighting has raged on...