Flames and a large plume of black smoke were spotted rising near Riyadh airport on Saturday, an eyewitness told Reuters.
The plume of smoke was allegedly rising from a fuel storage depot at King Khalid International Airport following Houthi strikes, Reuters reported.
The Saudi government media office did not immediately respond to a request for comment.
Saudi Arabia had been under attack from the Houthis early Saturday morning.
Saudi civil defense sent an all-clear on Saturday after issuing alerts for a second time for potential danger in Riyadh and the city of Al-Kharj east of the capital, amid an uptick in attacks by Iran-aligned Houthis on the Gulf country.
The alerts were the first for the capital since Houthis in neighboring Yemen intensified their attacks on Saudi Arabia.
A Reuters journalist heard two booms in Riyadh’s Olaya area.
The alerts come hours after the Houthis' military spokesperson said the group had foiled unspecified "criminal attempts" in the Yemeni capital Sanaa, blaming Saudi Arabia and vowing a response.
There was no immediate comment from the Saudi government's media office on the Houthis' statement.
Iran-backed Houthis seized Yemeni Red Sea ports
The Houthis, who control the most populous parts of Yemen and much of the north, have been launching attacks towards Saudi Arabia since declaring a naval blockade against Riyadh in July, with strikes targeting Saudi vessels in the Red Sea.
The Iran-aligned group, which seized Yemen's entire Red Sea coast in a lightning advance this month, says the Saudi Air Force has conducted hundreds of airstrikes in recent days.
The UN Security Council, in a statement on Friday, "condemned in the strongest terms continued Houthi attacks against the Kingdom of Saudi Arabia, including attacks impacting civilian and energy infrastructure, which have resulted in the injury of civilians, including women and children."
In the statement, the Security Council also condemned "Houthi military escalation in Yemen."