President Donald Trump threatened that the United States is 'locked and loaded' if Iran kills protesters, after cost-of-living demonstrations in the country turned deadly.

Protesters and security forces clashed in several Iranian cities on Thursday 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.

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 Republican leader added.

The senior adviser to Iran's Supreme Leader, Ali Larijani, responding to Trump's warning on Friday, said that US interference ​in Iranian protests ⁠would lead to chaos ​across the Middle East. 

An Iranian official also said US intervention in the country would 'destabilise [the] entire region'.  

Iran's biggest ⁠protests in three years over ⁠economic hardship have turned violent across several provinces, ‍leaving multiple people ⁠dead.

President Donald Trumpthreatened that the United States is 'locked and loaded' if Irankills protesters

Protesters and security forces clashed in several Iranian cities on Thursday with six reported killed in the first deaths since the unrest escalated. Pictured: Screengrab of footage shared online which appeared to show protesters clashing with the security force 

Riot squads opened fire and carried out mass arrests on protesters, who have vowed not to back down. 

More cities joined the protests as night fell on Thursday and clashes intensified in several locations, prompting officials to send reinforcements.  

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.

However, human rights groups have contradicted these reports, insisting he was in fact amongst the protestors and killed by security forces.

Crowds on the streets chanted anti-government slogans, such as 'this year is a year of blood, Seyyed Ali will be overthrown' and 'death to the dictator'.

Dozens of people were arrested by riot police and plainclothes agents.

Security forces also reportedly blocked roads, deployed a heavy armed presence to the streets, and engaged with the protesters.