The Iran-backed Huthis rarely comment on losses, and AFP could not independently verify the toll.

"Fourteen military vehicles were destroyed and more than 115" insurgents killed, the coalition which has been fighting in Yemen for nearly seven years said, according to the official Saudi Press Agency.

Marib, capital of the oil-rich province of the same name, is the internationally recognised government's last bastion in northern Yemen.

The strikes were carried out in the past 24 hours in Al-Jawba, about 50 kilometres (30 miles) south of Marib, and Al-Kassara, 30 kilometres northwest.

The coalition has since October 11 issued near-daily reports of bombing around Marib, saying it has since then killed around 2,300 insurgents in the area.

The Huthis began a major push to seize the city in February and, after a lull, they renewed their offensive in September.

A pro-government military official told AFP on Tuesday that the rebels have made "new advances amid ongoing clashes with pro-government troops", adding that 23 loyalists were killed in fighting in the past 24 hours.

Another loyalist official confirmed that the insurgents were edging closer to the city.

- 'Spare civilians' -

Huthi spokesman Yahya Saree said on Tuesday the rebels were on the "outskirts of Marib on several fronts", according to the Huthis' Al-Masirah TV channel.

"We will not hesitate to move forward, until we liberate all that is left," he added.

Saree's statements came two days after at least 22 people were killed in a Huthi rebel strike on a mosque south of Marib city, a pro-government official told AFP on Monday.

Yemen's Information Minister Moammar al-Eryani had said that 29 people, including women and children, were killed in the attack.

Last week, children were among 13 people killed when a missile fired by the rebels struck a tribal leader's home in Al-Jawba, according to military and medical officials.

The Norwegian Refugee Council urged both sides to ensure humanitarian aid can reach civilians in need.

"We call on all parties to spare civilians and ensure that we can keep reaching them with life-saving aid," said Erin Hutchinson, the NRC's country director in Yemen.

Yemen's civil war began in 2014 when the Huthis seized Sanaa, prompting Saudi-led forces to intervene to prop up the government the following year.

Tens of thousands of people have died and millions have been displaced in what the United Nations calls the world's worst humanitarian crisis.