Saudi Arabia’s air defences intercepted and destroyed a drone launched towards the kingdom by Yemen's Iran-backed Houthi rebels, the Saudi-led coalition supporting the Yemeni government said on Thursday morning. The interception was announced hours after the coalition said it received a distress call from an oil tanker facing armed harassment off Yemen’s Red Sea coast. The coalition had earlier said it monitored and documented “preparations for hostile action by an explosive-laden boat from the Yemeni port of Saleef”. The Houthis have increased aerial and maritime attacks amid reports of heavy losses on the battlefield. Earlier this week the rebels hijacked a United Arab Emirates-flagged cargo ship carrying medical supplies near Hodeidah, Yemen's main Red Sea port, the coalition said. The Yemeni army on Wednesday said that it made several advances against the rebels on several fronts in the northern province of Marib, while allied forces in the south this week reported significant gains in Shabwa province. The army's media centre said troops backed by the Popular Resistance forces launched a sweeping attack in Al Kasara area in western Marib and inflicted heavy losses on the rebels. The civil war in Yemen began in late 2014 when the Houthi rebels seized the capital, Sanaa, and much of the north, forcing the government to flee south. The Saudi-led coalition, backed at the time by the United States, entered the war months later to try to restore the government to power.