US President Donald Trump has said that the United States is "locked and loaded" to respond if Iran kills protesters, after cost-of-living demonstrations in the country turned deadly.
Protesters and security forces clashed in several Iranian cities yesterday with six reported killed in 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 to other parts of the country.
Mr Trump said on his Truth Social platform that if Iran shoots "and violently kills peaceful protesters, which is their custom, the United States of America will come to their rescue".
"We are locked and loaded and ready to go," the US leader added.
Iran has warned against any US intervention in the country.
"Any interventionist hand that attacks Iran's security under any pretext whatsoever will be exposed to a response," Ali Shamkhani, an adviser to the supreme leader, wrote on X.
"Iran's security is a red line."
Iran's Fars news agency reported yesterday that two people were killed in clashes between security forces and protesters in the city of Lordegan, in the province of Chaharmahal and Bakhtiari, and three in Azna, in neighbouring Lorestan province.
State television reported earlier that a member of Iran's security forces was killed overnight during protests in the western city of Kouhdasht.
The demonstrations are smaller than the last major incident in 2022, triggered by the death in custody of Mahsa Amini, who was arrested for allegedly violating Iran's strict dress code for women.
Her death sparked a nationwide wave of anger that left several hundred people dead including dozens of members of the security forces.
