The death toll in weeklong Iran unrest has climbed to at least 16, rights groups said Sunday, as protests over soaring inflation spread nationwide and sparked violent clashes between demonstrators and security forces.

Deaths and ‍arrests have been reported throughout the week, both by state media and rights groups, though the numbers have differed. Reuters has not been able to verify the figures independently.

The ‌protests are the biggest in three years and while smaller than ‍some previous bouts of unrest to rattle the Islamic Republic, they come at a moment of vulnerability with the economy in tatters and international pressure building.

U.S. President Donald Trump has threatened to come to the protesters' aid if they face violence, saying on Friday: "We are locked and loaded and ready to go" but without specifying any actions he was considering.

That warning prompted threats of retaliation against U.S. forces in the region from senior Iranian officials and Supreme Leader Ayatollah Ali Khamenei said Iran "will not yield to the enemy."