At least 73 people were wounded when Yemen’s Houthi rebels launched their heaviest attack on Saudi Arabia since the Middle East war reignited.
The Iran-backed rebels said they hit Abha International Airport, King Khalid air base and facilities belonging to state-owned oil giant Aramco in Abha and Jizan, near their shared border.
Saudi authorities and official media said the strikes caused fires and temporary shutdowns. It was the worst attack by the Houthis since a four-year truce in Yemen's long-running civil war unraveled in July.
Saudi Arabia will "take all necessary measures to defend its sovereignty," a Foreign Ministry statement said, demanding a halt to the Houthi strikes and their attacks on Red Sea shipping.
The Houthis triggered a return to hostilities in July when they let an Iranian plane land in Sanaa, in defiance of Saudi control of Yemeni airspace.
They are now pushing to seize Yemeni government-held territory along the Red Sea's southern gateway, with clashes leaving hundreds dead and forcing thousands of residents to flee.
The Houthis have also been attacking Saudi oil tankers in the Red Sea, a vital export route since Iran blockaded the Strait of Hormuz as part of its war with the United States.
A Saudi-led coalition, which has been fighting the Houthis on the government's behalf since 2015, said it would respond to the latest attacks.
"The Terrorist Houthi Militia's senseless attacks, the latest of which targeted civilian and economic sites," resulted in injuries to 73 civilians, said the coalition's Joint Forces Command.
"The Command will also take all necessary measures and actions to respond to the sources of the threat and neutralize its danger."
According to an Energy Ministry source quoted by the Saudi Press Agency, "several energy sector facilities and installations in the southern region of the kingdom were targeted this morning."
"The attacks caused fires at several locations, leading to a temporary halt in some operations" as well as several injuries, the source was quoted as saying.
The Houthi attacks came after they accused Riyadh Monday of carrying out strikes around Yemen, including the deadly bombardment of a prison.
The attack on the jail in al-Hazm in Yemen's north killed 11 people and left 20 inmates missing under the rubble, rebel TV channel Almasirah quoted Jawf province's civil defense chief as saying.
The rebels are also pressing their broad offensive along frontlines on the western Red Sea coast in a bid to advance towards the Bab el-Mandeb Strait, the mouth of the Red Sea.
About 18,500 people have been displaced in the flashpoint governorates of Taiz and Hodeidah, the United Nations' International Organisation for Migration estimated.
"The number is increasing by the hour," it said in a statement Monday.
