CAIRO—A tanker carrying badly needed fuel arrived in Yemen’s blockaded port of Hodeida on Sunday, as a cease-fire meant to stop the fighting in the war-torn country for two months entered its first full day. The truce agreement, which took effect Saturday evening, allows for shipments of fuel to arrive in Hodeida and for passenger flights to resume from the airport in the capital of Sanaa. Both Hodeida and Sanaa are held by the Iranian-backed Houthi rebels. The agreement comes after a significant escalation in hostilities in recent weeks that saw the Houthis claim several attacks across the country’s borders, targeting the United Arab Emirates and Saudi Arabia. Essam al-Motwakel, spokesman for the Houthi-run oil corporation, said the Saudi-led coalition allowed the vessel—carrying mazut, a low-quality fuel oil—into the port at Hodeida. The port handles about 70 percent of Yemen’s commercial and humanitarian imports. He called on U.N. envoy Hans …