Sanaa, Aug 26 : The Saudi-led Arab coalition launched extensive airstrikes on Houthi positions and their reinforcements in Yemen's central province of Marib in the past 24 hours, a military source said. The airstrikes targeted the Houthis in four frontlines in the western districts of Sirwah and Rahabah, killing dozens and destroying several vehicles carrying weapons and combatants, the source told Xinhua news agency. Meanwhile, the Houthi-run al-Masirah TV reported 17 coalition airstrikes in Sirwah and Rahabah in the last 24 hours, without providing further details. The Houthis began in February a major offensive on Marib in an attempt to seize control of the oil-rich province, the government's last northern stronghold. The UN has warned that the offensive on Marib, which hosts nearly 1 million internally displaced people, could lead to a major humanitarian catastrophe. The UN's recent peace proposal to end the war was publicly rejected by the Houthi group. Yemen's civil war flared up in late 2014 when the Iran-backed Houthi group seized control of much of the country's north and forced the internationally recognized government of President Abd-Rabbu Mansour Hadi out of the capital Sanaa. The Saudi-led coalition intervened in the Yemeni conflict in March 2015 to support Hadi's government. /IANS