Saudi Arabia told businesses not to send staff into Riyadh’s main financial zone after concerns that the area could be targeted in Iranian missile or drone attacks. The order to empty office towers in the King Abdullah Financial District (KAFD) is one of the clearest signs yet that the kingdom’s effort to maintain an atmosphere of “business as usual” is becoming hard to sustain as the threat of Iranian attacks persists.

KAFD instructed companies on April 2 to evacuate immediately and not to send back staff until at least April 6, according to people familiar with the matter and a notice seen by Semafor.

The evacuation order impacted the kingdom’s sovereign wealth fund and the offices of international banks. KAFD features some of the city’s most iconic towers and hosts the likes of Goldman Sachs and Deloitte.

People living in KAFD’s residential towers were advised to shelter in place, the people said. KAFD declined to comment. Some prominent commercial buildings elsewhere in Riyadh — including the Al Faisaliah Tower, which houses JPMorgan and Apple — were also evacuated over the weekend. The Wall Street Journal first reported on the evacuation notice.

Some companies with offices in the financial district said they had received informal instructions not to send staff into the area for several weeks.