Three Saudi nationals have been killed in two attacks on the international airport in the capital, Riyadh, the country's civil aviation authority has said after Yemen's Houthis said they targeted the facility.

The attacks also resulted in "injuries to a number of Saudi citizens and residents of various nationalities", the General Authority of Civil Aviation said in a statement on X.

It said the first attack on Thursday targeted the airport while the second one struck an aircraft belonging to state carrier Saudia.

One of its pilots was among those killed, the airline said in a statement.

Air traffic had returned to normal, the civil aviation authority said.

Yemen's Houthi group said on Thursday it had attacked the airport with two missiles, reports said.

The Iran-aligned group said it had also targeted an airport in Najran city near the Saudi border with Yemen, and Khamis Mushait air base further north. Saudi Arabia has not confirmed these attacks.

The latest casualties follow the deaths of three people in Houthi attacks on two Saudi airports on October 6 and 7.

Two were killed and 28 wounded in an attack at Abha International Airport, the civil aviation body said on Wednesday. Another person was killed at King Khalid airport.

The latest attacks come amid mark an escalation in renewed fighting between Yemen's Saudi-backed government forces and the Houthis, who control most of the country's north-west.

The Houthi military spokesperson said the previous two attacks on Saudi Arabia's airports were in "response to the Saudi aggression against our country" which saw "60 airstrikes and missile attacks in the past 24 hours".

The group says it is targeting Saudi Arabia over its support for government forces in Yemen's civil war.

The conflict has worsened in recent weeks, after the Houthis seized strategically important stretches of the Red Sea coast in a rapid offensive.

That included the port of Mokha on the Bab al-Mandab Strait, which is the narrowest point of the Red Sea and a chokepoint for global shipping.

But Yemeni pro-government forces have since said they had "secured" the Bab al-Mandab Strait at the southern end of the Red Sea.

A Saudi-led coalition was formed in 2015 after Arab countries joined forces to stop the Houthis taking over Yemen from the country's internationally recognised government.

A temporary ceasefire was brokered in 2022 after years of air strikes and ground fighting led to the deaths of hundreds of thousands of people, triggering one of the world's worst humanitarian crises.

But the informal ceasefire began to unravel in July.

The Houthis announced a "maritime embargo" against Saudi Arabia and began missile and drone attacks on Saudi airports, oil facilities and tankers in the Red Sea. They said they were retaliating for what they say is a years-long Saudi blockade, and for an air strike on Sanaa airport.