By Enas Alashray, Nayera Abdallah and Jana Choukeir
CAIRO/DUBAI, Sept 8 (Reuters) - Yemen's Tehran-backed Houthis attacked four cities in the south of U.S. ally Saudi Arabia on Tuesday, wounding more than 70 people and setting oil installations ablaze in what appeared to be a major expansion of the six-month-old Middle East war.
The Houthis, who control most of Yemen's populated areas including the capital, said they had launched a broad operation deep into Saudi territory. They used drones and missiles
to strike a Saudi airbase in the southern city of Khamis Mushair, and targets belonging to Saudi Arabia's state oil company in nearby Abha, Najran on the Yemeni border and Jazan, a major Red Sea port.
Saudi authorities described blazes at the sites and said women and children were among the 73 people hurt. The reports of such large numbers of wounded suggested the attacks were among the biggest carried out against Saudi Arabia since the United States and Israel launched their war against Iran in February.
Confirmed images of the aftermath of the attacks in the Saudi cities were not immediately available. The Houthis released pictures of an explosion of what they said were trucks from Saudi Arabia they had struck at the border in another area.
After a month of calm in August, fighting in the Gulf has resumed, with Iran and the U.S. exchanging fire, sending global oil prices back up to levels unseen since July. Brent crude prices were up more than 2% on Tuesday, above $99 a barrel.
Houthi attacks on southwestern Saudi Arabia have the potential to worsen the war's global economic impact by disrupting Middle East energy supplies beyond the blockaded Strait of Hormuz.
Saudi Arabia has led an Arab coalition battling against the Houthis in Yemen for more than a decade. That war had calmed in recent years, but a ceasefire there has broken down, with the Houthis threatening shipping at the mouth of the Red Sea.
'MARITIME EXCLUSION ZONE'
"The coalition will take all necessary operational measures to deter this terrorist militia and resolutely confronts its hostile approach," Colonel Turki al-Malki, spokesperson for the Saudi-led coalition, said in a statement on X.
Houthi spokesperson Yahya Saree accused Riyadh of having escalated the war by launching air strikes on Yemen, and said the Houthis would respond.
The war in the Gulf has turned into a test of wills between the U.S. and Iran, with each side hoping that economic pressure from competing blockades will force the other to yield.
Washington is trying to increase the flow of oil to world markets by guiding ships through the Strait of Hormuz at the mouth of the Gulf, while cutting off Iran's exports with a blockade just beyond it.
Tehran has announced new measures to seal off the strait, saying it will soon unveil details of a "maritime exclusion zone" that will extend from the perimeter of the U.S. blockade, through the strait and into the Gulf itself.
Washington fired at Iranian tankers over the weekend in retaliation for Iranian fire at U.S. warships. Iran said it had used new, more capable ballistic missiles to attack American ships.
"In recent days, Washington has received a clear warning from Iran’s new missiles," Mohsen Rezaei, secretary of Iran's Supreme National Security Council said on X. "Economic warfare will be met by a maritime exclusion zone across the Persian Gulf to the blockade perimeter. The operational posture toward U.S. warships and bases has been fundamentally recalibrated."
Despite U.S. barrages that have degraded Iran's conventional forces and punished its already ailing economy, Iran still possesses missiles and drones that can threaten oil tankers transiting the Strait of Hormuz and have been used to attack U.S. military bases scattered throughout the region.
About a fifth of global oil and liquefied natural gas shipments passed through the strait before the war.
The fighting has caused global shortages of crude oil and, even more acutely, the fuels that are produced by refining it. Diesel fuel in the United States is now at a record average retail price of more than $5.90 a gallon, harming the political prospects of President Donald Trump's Republicans.
"Oil prices will drop precipitously, like everything else is dropping (but more!), when we WIN the war with Iran. Three Dollars a gallon, but ultimately, below Two Dollars a gallon. It will all happen quickly, and Iran will never have a Nuclear Weapon," Trump said on social media.
(Reporting by Enas Alashray in Cairo, Nayera Abdallah, Eman Abouhassira and Jana Choukeir in Dubai; Writing by Daniel Trotta, Lincoln Feast, Peter Graff, Editing by Editing by Michael Perry, Stephen Coates and Timothy Heritage)
