Tribes in Marib have mobilized thousands of fighters and armoured cars to fight Houthi militants and dissident forces loyal to ex-president.
Tribal elders revealed on Monday that around 30.000 fighters with necessary arms and vehicles have already taken their positions to prevent Houthi militants from advancing toward their city.
Moreover, our fighters were ordered to advance toward Sanaa and Saada cities in case Houthi militants and pro-Saleh forces decided to attack us, the elders said.
Houthi militants have recently threatened to take over the oil-rich Marib after they tightened grip on power in the capital Sanaa.
The militants have been fighting tribes in adjacent cities for more than a year. They have been stuck in Baidha, Jawf and Sanaa and can't advance into the well-fortified and heavily armed Marib.
Separately, military sources in southern city of Lahj said today Houthi militants and pro-Saleh forces have fled the Anad Military base after fierce battles with popular resistance committees.
The sources said Arab jets have repeatedly struck the base and helped the resistance to take over it.
Arab countries launched a military operation in Yemen twelve days ago.
Their jets have destroyed key military bases, brigades and weapons controlled by Houthis in several cities.
Meantime, popular resistance committees in southern Aden and Dhale cities are continuing their battles against the Houthi militants.
With support from pro-Saleh forces, the militants have been fighting on several warfronts in the south for weeks.
They are seeking to control the while country after the UN-backed transition process failed.