Iman Saleh Ali and her family left al-Jubah in the dead of night with only the clothes on their backs, to escape fighting between government forces and their Houthi foes.It's the second time the family has been forced to flee the battle for Yemen's Marib.With no means to afford accommodation, they now wait for assistance, huddled with 25 other families in a make-shift camp in Wadi Abida, east of Marib City, which is already home to hundreds of thousands of displaced Yemenis."We didn't bring a single thing with us, not even a blanket, we just fled one after the other, we didn't take with us food or blankets or heating, we barely escaped ourselves, because of this war."The United Nations says some 10,000 people were displaced last month alone by the fighting in Marib governorate, the internationally recognized government's last northern stronghold. It is calling for a humanitarian corridor for aid.The fighting in Yemen is exacerbating a humanitarian crisis that has left millions on the verge of famine and 20 million people needing help.U.N. humanitarian coordinator in Yemen David Gressly called on the warring sides to allow assistance through. He said 200-250 Yemeni civilians are killed a month in the war."We call on all the parties to take extra measures now to avoid those kinds of casualties, to spare the civilians, the children, women, men, from this extra burden on the war, it is bad enough on the economy but to lose that many lives every month is unacceptable.Tens of thousands of Yemenis have been killed since a coalition led by Saudi Arabia intervened against the Iran-aligned Houthis in late 2014, after the Houthis ousted the government from power.