President Donald Trump said on Friday that the United States was "locked and loaded" to respond if Iran killed protesters, prompting Tehran to warn that intervention would destabilize the region.
Protesters and security forces clashed in several Iranian cities on Thursday, with
six people reported killed, the first deaths since the unrest escalated.
Shopkeepers in the capital Tehran went on strike on Sunday over high prices and economic stagnation, actions that have since spread into a protest movement that has swept into other parts of the country.