Saudi Arabia issued security alerts over a range of territory on Tuesday, including in the holy city of Mecca and second-largest city Jeddah, following a week of attacks from Iran-aligned fighters that have drawn it deeper into the Middle East war.

The alerts were swiftly lifted and Saudi authorities did not immediately report whether any incoming projectiles had landed, nor was there any immediate claim of responsibility for attacks.

But the alerts were the widest ranging since an escalation in the conflict last week, and the alarm in Mecca was the first of the war in the city, which houses shrines sacred to all Muslims.

The Iran-backed Houthis in Yemen have announced a number of major attacks on Saudi Arabia over the past week, including strikes on an air base on Monday they said were in retaliation for airstrikes on Yemen.

Saudi Arabia has blamed a separate pro-Iranian movement, based in Iraq, for an attack on Friday that knocked out one of the Kingdom’s most important oil transport routes, the East-West Pipeline across the Arabian desert.

A Saudi-led military coalition fighting against the Houthis in Yemen said 13 civilians had been wounded in Monday’s attacks by the Houthis on Saudi Arabia.

The Iran-backed fighters launched a lightning advance along Yemen’s western coast last week, culminating in the seizure of an island in the mouth of the Red Sea.

The escalation in a new theatre in the Middle East conflict has strengthened Iran’s hand in its war with the US and further jeopardised global oil supplies.

Officials from a Saudi-backed Yemeni government, which is based in the south of the country and opposes the Houthis, said the Saudi and Yemeni air forces had been responding to Houthi advances by stepping up aerial bombardment of Houthi targets. That included strikes near the historic Red Sea port of Mocha, which the fighters captured last week.

But the Yemeni officials acknowledged that the Houthis had now taken effective control over almost the entire western coast of the country along the Red Sea.

“The Houthis are being put under heavy pressure. They in turn are putting more and more pressure on the Saudis, increasing their campaign of missile and drone attacks,” of the Yemeni officials said.