A civilian plane was engulfed in flames in an attack Wednesday by Yemen's Huthi rebels on an airport in southern Saudi Arabia, the Riyadh-led coalition battling the insurgents said. 

"A cowardly criminal terrorist attack launched against Abha International Airport in Saudi Arabia by the Huthi militia," state-run Al-Ekhbariya television cited the coalition as saying.

"A fire that engulfed a passenger plane due to the Huthi attack on Abha Airport is under control," it added.

The coalition did not report any casualties, or say how the attack was carried out, but earlier in the day reported it had intercepted two "booby trap" drones in the south.

The incident was not immediately claimed by the Iran-backed Huthis.

But the rebels appear to be stepping up attacks on the kingdom as well as on Riyadh-backed Yemeni forces after the United States moved last week to delist the Huthis as a terrorist group.

The Huthis have also resumed an offensive to seize the Yemeni government's last northern stronghold of Marib, according to a government source, with dozens of casualties on both sides. 

The US State Department on Friday said it had formally notified Congress of its intention to revoke a terrorist designation against the rebels, which had been announced at the end of the administration of former president Donald Trump.

The delisting move came a day after US President Joe Biden announced an end to US support for Saudi-led offensive operations in Yemen.

Humanitarian groups were deeply opposed to the designation, saying it jeopardised their operations in a country where the majority of people rely on aid, and that they have no choice but to deal with the Huthis, who control much of the north.

Saudi Arabia, which entered the Yemen conflict in 2015 to bolster the internationally recognised government, has repeatedly been targeted with cross-border attacks.

Last month, it said it had intercepted and destroyed a "hostile air target" heading towards the capital Riyadh.

Huthis claim drone attack on Saudi airport

Yemen's Iran-backed Huthi rebels said they undertook a drone attack on a Saudi airport that left an aircraft in flames Wednesday, saying the facility was used to launch attacks on Yemen.

"The UAV air force targeted the airfields of warplanes at Abha International Airport - which is used for military purposes to target the Yemeni people - with four drones," Yahya Sarie, spokesman for the Huthis' armed wing, said in a tweet.

"The strike was accurate, thanks to God."