⚡ Yemen’s Houthi group warned shipping companies in an email to avoid loading or unloading cargo at ports in Saudi Arabia.

Based on a report by Reuters, the email said that such activity could lead to these companies being targeted “anywhere.”

The Houthis announced on Monday that they are imposing a “maritime blockade” on Saudi Arabia. The move could open a new front against the United States in its war with the Islamic Republic and expand threats to global energy supply and trade beyond the Persian Gulf.

Saudi Arabia’s Ministry of Foreign Affairs condemned the decision and said the country would take “all necessary measures” to protect its ships.

The closure of the Strait of Hormuz has forced Saudi Arabia to transfer much of its oil exports to the port of Yanbu in the Red Sea—a route that is now the target of the Houthis’ threats.