Iran will offer no leniency to "rioters", though the public has a right to demonstrate, the head of the country's judiciary said on Monday, following more than a week of sometimes-deadly protests.

The remarks came after US President Donald Trump warned Iran would "get hit very hard by the United States" if the authorities killed more demonstrators.

Protests erupted on December 28 when shopkeepers in capital Tehran staged a strike over high prices and economic stagnation. They have since spread to other cities and expanded to include political demands.

"I instruct the attorney general and prosecutors across the country to act in accordance with the law and with resolve against the rioters and those who support them... and to show no leniency or indulgence," Gholamhossein Mohseni Ejei said, according to the judiciary's Mizan news agency.

He went on to add that Iran "listens to the protesters and their criticism, and distinguishes between them and rioters".

UN Secretary-General Antonio Guterres called on Iran to respect the demonstrators' right to peaceful protest, according to his spokesman Stephane Dujarric, underscoring "the need to prevent further casualties".

"All individuals must be allowed to protest peacefully and express........

© Al Monitor