Yemen's Houthi rebels have made major gains in the battle for the government's last northern stronghold, advancing close to the center of Marib city despite heavy casualties, military sources said Sunday.
The rebels have taken full control of the Kassara battlefield to the northwest and made progress on western front lines despite airstrikes by the Saudi-led coalition that backs Yemen's government, the loyalist military sources said.
Marib and its surrounding oil fields make up the last significant pocket of government-held territory in the north, the rest of which is under rebel control, including the capital Sanaa.
Fierce fighting has left at least 65 dead over the past two days alone, including about 25 loyalist personnel, among them four officers, the government sources told AFP.
The Iran-backed Houthis rarely disclose their own losses.
The loyalist officials said fighting had now moved to the Al-Mil area, 6 kilometers (4 miles) from the center of Marib, they said.
However, mountains around Al-Mil remain a formidable barrier to the rebels who have been battling to reach Marib since February.
The government sources said the Houthis had poured in hundreds of reinforcements in recent days, resorting to motorbikes after the coalition targeted their military vehicles.
But the Yemeni government's Information Minister Moammar al-Eryani on Sunday disputed Agence France-Presse's reporting of Houthi rebel gains and denied that the Houthis had taken Kassara.
"We confirm that National Army & Popular Resistance in Marib are steadfast in their positions on various fronts," he wrote on Twitter.
The loss of Marib would be a major blow for the Yemeni government and for Saudi Arabia, which has supported the government militarily since March 2015, after the rebels captured Sanaa.
Observers say the Houthis are intent on capturing the city in order to gain leverage before entering into any negotiations with the government, amid a U.S. push to revive peace talks.
The city's fall could also lead to a humanitarian disaster, as vast numbers of civilians displaced from fighting elsewhere have sought refuge in the area.
Around 140 camps have sprung up in the surrounding desert to provide basic shelter for up to 2 million displaced people, according to the Yemeni government.
Hundreds of combatants have been killed since the large-scale offensive began, with the toll fueled by wave after wave of Houthi fighters arriving on front lines around the city.
A government commander told AFP in Marib earlier this month that the Houthis are deploying young recruits, many of them children, with the goal of wearing down loyalist forces and depleting their ammunition.
These recruits are used in first wave attacks, followed by a more lethal wave of experienced Houthi fighters under the cover of constant shelling, the commander said of a rebel strategy that is heaping pressure on loyalist forces.
The escalation in hostilities has displaced 13,600 people in Marib this year, according to the U.N. refugee agency, putting a heavy strain on the city during a second coronavirus wave.
Lacking clean water and electricity, makeshift settlements are overflowing, and camp residents say they have repeatedly come under Houthi shelling.
The rebels have also stepped up missile and drone strikes against neighboring Saudi Arabia in recent months, demanding the opening of Yemen's airspace and ports. They have rejected a Saudi proposal for a cease-fire.
The administration of U.S. President Joe Biden is mounting a renewed push to end the conflict, warning that the suffering will only end when a political solution is found.