DUBAI: US President Donald Trump threatened on Friday to come to the aid of protesters in Iran if security forces fire on them, days into unrest that has left several dead and posed the biggest internal threat to Iranian authorities in years. “We are locked and loaded and ready to go,” he said in a social media post. The United States struck Iranian nuclear facilities in June, joining an Israeli air campaign that targeted Tehran’s atomic programme and military leadership. Top Iranian official Ali Larijani responded to Trump’s comments, warning that US interference in domestic Iranian issues would equal the destabilisation of the whole region. Iran backs groups in Lebanon, Iraq and Yemen. The comments came as a local official in western Iran where several deaths were reported was cited by state media as warning that any unrest or illegal gatherings would be met “decisively and without leniency”, raising the likelihood of escalation. This week’s protests over soaring inflation have spread across Iran, with deadly confrontations between demonstrators and security forces focused in western provinces. State-affiliated media and rights groups have reported at least six deaths since Wednesday, including one man who authorities said was a member of the Basij paramilitary affiliated with the Revolutionary Guards. Iran has seen off repeated bouts of major unrest in recent decades, often quelling protests with heavy security measures and mass arrests. But economic problems may leave authorities more vulnerable now.