Sanaa, Sep 21 : At least 35 Houthi rebels were killed when Saudi-led airstrikes hit Houthi reinforcements in Yemen's central province of Marib, a government military source said. "The airstrikes targeted four convoys of the rebel reinforcements in and around the western Sirwah district, destroying 13 pick-up vehicles and killing 35 Houthis rebels," the source told Xinhua news agency on Monday. Meanwhile, the Houthi-run al-Masirah TV reported 23 Saudi-led coalition airstrikes on Sirwah without providing further details. Sirwah is a main frontline between the rebels and the Yemeni army in Marib. The Iran-backed Houthi militia launched 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