Mass surrender: 5000 Saudis captured
Yemen's Houthi movement says it has carried out a major attack near the border with the southern Saudi region of Najran and claims three "enemy military brigades" have fallen.
Claims of the attack comes just two weeks after an Iran-backed missile strike on Saudi's main oil plant, which sparked a spike in global petrol prices.
The oil plant strikes also heightened tensions between Iran and the US with President Donald Trump threatening the nation, saying the US is better prepared for war than any other country.
American officials claim Iran Supreme Leader Ayatollah Khamenei's "fingerprints" were all over the Saudi oil plant blitz and satellite images showed his henchmen preparing the launch site.
SAUDI OIL ATTACK
Trump warned the US military was "locked and loaded" - responding to Tehran's threat that it is "ready for fully-fledged war".
There was no immediate confirmation from Saudi Arabian authorities but the Houthis' military spokesman said the attack was launched 72 hours ago and supported by the group's drone, missile and air defence units, The Sun reports.
But if the claims are true, the attack could prove one of the most significant events in the Middle East in recent years.
It comes as a brutal civil war rages in Yemen and has claimed more than 16,000 lives and left 13 million people on the brink of starvation.
The conflict has been dubbed a "proxy war" among competing powers in the Middle East as a US-backed Saudi-led coalition battles rebels backed by Iran.
Houthi-run Al Masirah TV quoted the spokesman as saying the Iran-aligned movement had captured "thousands" of enemy troops, including many officers and soldiers of the Saudi army, as well as hundreds of armoured vehicles.
The spokesman for a Saudi-led military coalition that has been battling the Houthi group for over four years in Yemen did not immediately respond to a request for comment.
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 United Nations' 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.
The Sunni Muslim coalition, which receives arms and intelligence from Western countries, intervened in Yemen in March 2015 after the Houthis ousted the internationally recognised government from power in the capital Sanaa in 2014.
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.
Houthi spokesman Mohammed Abdul-Salam tweeted: "Operation 'Victory from God' is the largest military one since the brutal aggression began.
"The enemy suffered heavy losses ... and wide swathes of territory were liberated in only a few days,"
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 Sept. 14.
Riyadh dismissed the claim, saying the assault did not come from Yemen and instead blamed its regional foe Shi'ite Muslim 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 conflict is widely seen as a proxy war between Saudi Arabia and Iran.
The Houthis, who control Sanaa and most big urban centres, deny being puppets of Tehran and say they are fighting a corrupt system.