Iran’s Armed Forces Chief of Staff said security forces will not allow any terrorist group to operate or maneuver inside the country.

He stressed that Iran’s security and intelligence agencies remain fully prepared to counter threats and maintain stability.

Iran is facing its most intense wave of unrest in years as anger over a collapsing economy has triggered nationwide demonstrations and prompted authorities to impose a sweeping shutdown of internet and telephone services. Iran has closed the main airport in Tehran and deployed air defence systems nationwide, according to international aviation notices, as anti-government demonstrations intensified significantly on Thursday night.

The disruption, confirmed by watchdog groups including NetBlocks, has obscured the true scope of the protests but has done little to quell them.

The unrest comes at a moment of extraordinary pressure for Tehran, still grappling with the aftermath of a 12-day conflict with Israel in June, during which the United States carried out strikes on Iranian nuclear sites. The economic pain deepened further in September when the United Nations reinstated sanctions linked to Iran’s nuclear activities, accelerating the free fall of the rial, which has plunged past 1.4 million to the dollar.

Against this backdrop, U.S. President Donald Trump has issued unusually stark warnings to Iranian authorities, saying Washington would intervene if security forces “violently kill peaceful protesters,” adding that the U.S. “will come to their rescue.” Trump said Sunday: “We’re watching it very closely. If they start killing people like they have in the past, I think they’re going to get hit very hard by the United States.”