Cairo - A UN humanitarian agency warned in a report Tuesday that thousands of Yemeni civilians caught in fierce clashes between warring factions are trapped in an embattled northern district.

The number of displaced in the district of Hajjah has doubled over the past six months, said the UN Office for the Coordination of Humanitarian Affairs, or OCHA.

The impoverished governorate is home of Yemen’s most recent flashpoint district of Kusher where “thousands of civilians are reportedly trapped between conflicting parties,” it said.

“It is outrageous that innocent civilians continue to die needlessly in a conflict that should, and can be solved,” said Lise Grande, the UN humanitarian coordinator in Yemen.

Yemen’s Iran-backed Al Houthi militia imposed tight control over Kusher after powerful local tribesmen took up arms against them.

The district’s tribes, in a deal with Al Houthis, had remained neutral in Yemen’s civil war, which erupted in 2014, and were in return left in peace on their lands. But after Al Houthis tried to use the district to send weapons and reinforcements to a coastal area where they have been fighting Saudi-backed forces, the deal collapsed.

Al Houthis subsequently shelled the district - home to 100,000 people - and killed and wounded scores of civilians. Thousands were displaced. As A; Houthi siege strangled the area, the Saudi-led coalition airdropped food and medicine to the tribes.

Yemen’s civil war has killed over 60,000 people - both civilians and combatants - and displaced 3 million, pushing the already impoverished nation to the brink of famine.