DUBAI (Reuters) - Thousands of Iranians carrying signs reading “I’m a Guard too” and “Down with USA” marched on Friday to protest against the U.S. designation of the elite Revolutionary Guards as a foreign terrorist organization.

State television showed crowds shouting “What’s America thinking? Iran is full of Guards” after leaving Friday prayers at Tehran University on their way to a rally in a nearby square. Similar state-sponsored protests were held across Iran, it said.

Iranian officials have condemned U.S. President Donald Trump’s decision on Monday to blacklist the Islamic Revolutionary Guards Corps (IRGC), a step is likely to raise tensions in the Middle East.

Tehran retaliated by naming the regional United States Central Command (CENTCOM) as a terrorist organization.

“Americans should know that this is a self-inflicted blow, meaning that they are jeopardizing the security of their own troops in CENTCOM and across the world,” General Kioumars Heydari, head of the regular army’s ground forces, was quoted as saying on Friday by the semi-official ISNA news agency.

The estimated 125,000-strong Revolutionary Guards also command the volunteer paramilitary Basij and control Iran’s ballistic missile program. The Guards’ overseas Quds forces have fought Iran’s proxy wars in the region.

The United States has already blacklisted dozens of entities and people for affiliations with the IRGC, but had not previously targeted the organization as a whole.

“Today, it has been proven to the people of the world and of this region in particular that America is the mother of all terrorism,” said Tehran Friday prayers leader Ayatollah Mohammadali Movahedi Kermani, clad in a Revolutionary Guards uniform, state media reported.

The long-tense relations between Tehran and Washington took a turn for the worse last May when Trump pulled out of a 2015 nuclear deal between Iran and six world powers, reached before he took office, and reimposed sanctions.

Revolutionary Guards commanders have repeatedly said that U.S. bases in the Middle East and U.S. aircraft carriers in the Gulf are within range of Iranian missiles.

Tehran has also threatened to disrupt oil shipments through the Strait of Hormuz in the Gulf if the United States tries to strangle Iran’s economy by halting its oil exports.