UN humanitarian chief “very alarmed” by Houthi rebel advance on Yemen government’s last northern stronghold, says an assault on Marib could endanger millions of civilians.

People inspect the wreckage of a drone aircraft that Houthis say they shot down near the northwestern city of Saada, Yemen April 19, 2019.
People inspect the wreckage of a drone aircraft that Houthis say they shot down near the northwestern city of Saada, Yemen April 19, 2019. (Reuters Archive)

The Saudi-led coalition fighting Yemen’s Houthis has said it intercepted a drone fired allegedly by the Iran-aligned group that left shrapnel in the vicinity of Abha airport in Saudi Arabia.

The incident caused no casualties, the coalition statement carried by state-run Ekhbariya TV said. The explosive-laden drone had been fired towards Abha airport, which is in southern Saudi Arabia near the Yemen border.

The Houthis say they have launched attacks which have struck an airport or military air base in southern Saudi Arabia almost every day for the past 10 days.

The coalition says it intercepts and destroys most of them, but last Wednesday Riyadh said one attack had caused a fire in a civilian aircraft at Abha airport.

The coalition intervened in Yemen in 2015, backing government forces fighting the Houthis who control the capital and most populous areas. UN officials are trying to revive peace talks to end the war, which the United Nations says has created the world's largest humanitarian crisis. 

READ MORE: Deadly clashes in northern Yemen as Houthis ramp up attacks

'Very alarmed'

The UN’s humanitarian chief said on Tuesday he was "very alarmed" by a Houthi rebel advance on the Yemeni government’s last northern stronghold, saying an assault on Marib could endanger millions of civilians.

The Iran-backed Houthis have this month resumed an offensive to seize oil-rich Marib, some 120 kilometres (75 miles) east of the rebel-held capital Sanaa. 

The city's loss would be a major blow for Yemen's government, but also for the civilian population and the hundreds of thousands of displaced people sheltering in desolate camps in the region.

"I’m very alarmed about the military escalation in Marib and its impact on the humanitarian situation," Mark Lowcock, the UN undersecretary general for humanitarian affairs, said in a tweet.

"An assault on the city would put two million civilians at risk, with hundreds of thousands potentially forced to flee – with unimaginable humanitarian consequences. Now is the time to de-escalate, not to add even more to the misery of the Yemeni people."

Military officials told AFP that the rebels had advanced towards the city on two fronts overnight after heavy fighting with government forces. 

Dozens from both sides have been killed in the past 24 hours alone, they said. The total casualty toll from the battle for Marib is unknown but reports indicate it is now in the hundreds.

"The rebels have advanced north  and west of the city after seizing Al Zor (in Sirwah district) up to the western sides of Marib dam, and tightened their grip on hills overlooking supply lines for several fronts," one of the officials said. 

The military coalition, which entered Yemen's conflict in 2015, has been pounding rebel positions, and the Houthi-run Al Masirah television on Tuesday reported 13 airstrikes in several areas in Marib.

READ MORE: Flare up in Yemen conflict leaves dozens dead

Once a sanctuary 

The fighting is endangering sprawling camps for internally displaced people, many of whom have fled several times before ending up in Marib, the only part of the north not in Houthi hands.

Until early 2020, Marib city was spared the worst of Yemen's six-year-old conflict, due to its strategic importance with its rich oil and gas reserves, and also because of its location near the border of regional power Saudi Arabia.

It became a sanctuary for many in the early years of the war, taking in those hoping for a new start.

But that relative stability went with fighting last year and – after a lull since October – residents once again risk being in the line of fire as the two sides battle for control.

"If fighting moves towards populated areas or these displacement sites, we will see people flee again and towards locations to the east and south of Marib city with even less resources," International Organization for Migration spokeswoman Olivia Headon told AFP.

"Much of this is desert area so just think about what any displacement in that direction would mean for families' access to water." 

Headon said around 650 families had been forced to flee in the recent upsurge of fighting and that another shift in the front lines would lead to further waves of displacement.

Yemen's grinding conflict has claimed tens of thousands of lives and displaced millions, according to international organisations, sparking what the UN calls the world's worst humanitarian crisis.

The upsurge in violence comes shortly after Washington decided to remove the rebels from its list of terrorist groups – a move that would come into effect on Tuesday – in order to ensure aid is unimpeded, and to pave the way to restart peace talks.

Observers say the Houthis want to capture Marib as leverage before entering into any negotiations.

READ MORE: 400,000 Yemeni children under 5 in danger of death by acute malnutrition