Employees of American companies are “urged to leave these areas immediately,” according to a statement on the Revolutionary Guards website.
"These areas will soon become targets for the Islamic Revolutionary Guard Corps," the organization wrote.
It is unclear which companies are targeted, but the state-run Tasnim news agency has published a list of potential targets on social media, including offices of tech giants such as Amazon, Google, Microsoft and Nvidia.
Wave of attacks against major cities
Iran's newly appointed Supreme Leader, Ayatollah Mojtaba Khamenei, has in parallel decided that General Mohsen Rezaei, who previously led the Revolutionary Guard, will be his new military advisor, state media proclaimed.
Israel carried out a "large-scale wave of attacks" against the three major Iranian cities of Tehran, Shiraz and Tabriz on Monday.
Tehran was also attacked overnight. Mehrabad Airport was hit and a plane belonging to the Supreme Leader was destroyed, according to the Israeli military.
Instability in the region has also continued with new Iranian attacks around the Middle East.
A fire broke out at an oil facility at the port of Fujairah in the United Arab Emirates after a drone attack, the latest in a series of attacks on the site. State oil giant ADNOC has decided to pause deliveries to the facility's oil depots, a source said.
A drone attack also caused a fire in a major oil field outside Abu Dhabi.
Call details
In Baghdad, an airport and facilities, including a hotel, in the so-called Green Zone were attacked. In Saudi Arabia, more than 60 drones were reportedly intercepted overnight, and in Dubai a drone attack temporarily closed the city's only international airport. In Abu Dhabi, a man was killed when his car was hit by a missile attack.
US President Donald Trump has repeatedly said in the past 24 hours that the US is holding talks with Iran.
Direct contact has also reportedly been made between US envoy Steve Witkoff and Iranian Foreign Minister Abbas Araghchi in recent days, an American source with insight into the matter told the news site Axios. The contact reportedly consisted of text messages.
Araghchi denied contacts as recently as Sunday.
"We see no reason why we should talk to the Americans," he told US broadcaster CBS.
