Some Western and Saudi firms in Riyadh have extended work-from-home advisories this week, five people familiar with the matter ​said, amid concern over a looming US-imposed deadline for Iran ‌to open the Strait of Hormuz or face “hell”.

In Gulf states, which have borne the brunt of Iran’s attacks since the war began on February 28, ​many fear a US escalation would see Iran further ​target critical and civilian infrastructure in the Gulf in ⁠response.

The advisories, sent out on Monday and Tuesday individually ​by companies via email or text, affect work in Riyadh’s King ​Abdullah Financial District, Faisaliah Tower, Business Gate and Laysen Valley, the people said.

These locations host offices for major US banks and tech firms such ​as Microsoft and Apple, but also Saudi entities, including the ​sovereign wealth fund.

Employees were first told to work from home at the beginning ‌of ⁠last week, the people said, after Iran threatened to strike major US tech firms in the region in response to US-Israeli attacks and assassinations.

The Saudi government media office did not immediately respond ​to a request ​for comment.

Saudi ⁠has faced hundreds of Iranian drone and rocket attacks since the war began but says it has ​intercepted the vast majority. It has been less ​affected than ⁠other Gulf states, such as the UAE and Kuwait.

On Tuesday, Saudi Arabia said it intercepted and destroyed seven ballistic missiles launched ⁠towards ​its Eastern Region, with debris falling near ​energy facilities. Iran’s semi-official Fars news agency said a petrochemical complex in Saudi ​Arabia’s Jubail industrial city was attacked.