Yemen's Houthi movement said on Saturday it had carried out a major attack near the border with the southern Saudi region of Najran and captured many troops and armored vehicles, but there was no immediate confirmation from Riyadh.

The Houthis' military spokesman said in a statement that three "enemy military brigades had fallen" in the attack, which he said was launched 72 hours ago and supported by the group's drone, missile and air defense units.

Al Masirah TV quoted the spokesman as saying they had captured "thousands" of enemy troops, including many officers and soldiers of the Saudi army, as well as hundreds of armored vehicles.

Yemeni government troops, supported by coalition air strikes, have in recent months been fighting Houthi forces in the Kataf region of the northern Saada province near the Saudi border. Local sources have said the Houthis had captured scores of Yemeni forces in the battles.

The violence could hamper UN' efforts to ease tensions and pave the way for talks to end the war that has killed tens of thousands and pushed millions to the brink of famine in the long-impoverished Arabian Peninsula nation.

A UN-brokered prisoner swap deal agreed between the Houthis and Yemen's Saudi-backed government last December involving some 7,000 detainees on each side has yet to happen.

The Houthis, who had recently stepped up missile and drone attacks on Saudi cities, have claimed responsibility for the largest-ever attack on Saudi oil facilities on September 14.

Riyadh dismissed the claim, saying the assault did not come from Yemen and instead blamed its regional foe Iran. Tehran denies the charge.

The Houthis said on September 20 they would halt missile and drone attacks on Saudi Arabia if the alliance stopped its operations. The coalition has yet to respond to the proposal.

The war in Yemen broke out in 2014 with an offensive by the Houthis against the Yemeni government.