Sanaa, Nov 2 : At least 18 Houthi rebels were killed in an overnight airstrike by the Saudi-led coalition in Yemen's central province of Marib, a Yemeni government military source has said "The airstrike hit the rebels while they were gathering under a tree in the centre of Al-Jubah district, killing the 18 on the spot," the source in Al-Jubah frontline told Xinhua on condition of anonymity. Houthi-run al-Masirah TV reported late on Sunday nine coalition airstrikes on the Houthi positions in Al-Jubah without providing further details, Xinhua news agency reported. Last week, the Houthi group said they captured Al-Jubah in southern Marib after deadly fighting with the Yemeni government forces. The Iran-backed Houthi militia began in February a major offensive on Marib in an attempt to seize control of the oil-rich province, the last northern stronghold of the Saudi-backed Yemeni government. /IANS