The attack on Najran, about 10 miles north of the Saudi border with Yemen, was carried out by one Qasef K-2 drone armed with an explosive warhead and targeted a Saudi airport and military facility, the Houthi news outlet Al Masirah said. The broadcaster added that the drone struck an "arms depot," causing a fire.
Najran has repeatedly been targeted by the Houthis since the Saudi-led war in Yemen began four years ago. Saudi Arabia and the United Arab Emirates are leading a Western-backed coalition of Sunni Muslim states seeking to restore the internationally recognized government ousted from power in Yemen by the Houthis in late 2014.
There were no immediate reports of injuries or damage.
On Tuesday morning, in a statement carried by the Saudi Press Agency (SPA) and reported in the pro-regime newspaper Arab News, Colonel Turki Al-Maliki, the spokesman of the Saudi-led military coalition fighting the war in Yemen, said Houthi militants had tried to hit a civilian facility in Najran with a drone carrying explosives.
"The Houthi-backed terrorist militia of Iran continues to carry out acts of terrorism that pose a real threat to regional and international security by targeting civilian objects and civilian facilities, as well as civilian citizens and residents of all nationalities," Al-Maliki said in the statement.
Saudi Arabia initially declared on Twitter that it had intercepted two "Iranian-made" missiles fired against the province of Mecca, many miles to the north, but Houthi rebels denied targeting Mecca, Islam's holiest site.
Houthi commanders called the claim a tactic by Saudi Arabia to rally support for its war in Yemen. "The Saudi regime is trying, through these allegations, to rally support for its brutal aggression against our great Yemeni people," Houthi military spokesman Yahya Sarea said on Facebook, according to a Reuters report.
The attack came after Iran announced it quadrupled its uranium-enrichment production capacity a year after President Donald Trump withdrew the United States from the Iran nuclear agreement with world powers, designed to limit Iran's nuclear production capabilities. Iran's recent boost in nuclear material is still at a level far lower than required for production of nuclear weapons.
Riyadh has accused Iran of ordering last week's drone strikes on two oil pumping stations in the kingdom, for which the Houthis claimed responsibility. Tehran denied responsibility for the strikes.