Iran’s supreme leader has blamed the protests racking his country on “enemies of Iran” who he said were meddling in its internal affairs.

Ayatollah Ali Khamenei’s first public remarks since the demonstrations began came as state television reported that overnight clashes between protesters and security forces had killed another nine people.

The demonstrations, the largest in Iran since its disputed 2009 presidential election, have brought six days of unrest across the country and resulted in at least 21 deaths.

The protests began on Thursday in Mashhad over Iran’s weak economy and a rise in food prices.

They have since expanded to several cities, with some protesters chanting against the government and the Ayatollah.

Hundreds of people have been arrested and a prominent judge has warned that some could face the death penalty.

In comments posted to his official website, the Ayatollah appeared to blame foreign nations for exacerbating the unrest.

“In the recent days’ incidents, enemies of Iran utilised various means — including money, weapons, politics and intelligence apparatuses — to create problems for the Islamic system,” he said.

Supreme Leader Ayatollah Ali Khamenei
Supreme Leader Ayatollah Ali Khamenei (Office of the Iranian Supreme Leader via AP)

Iranian leaders often accuse the US, Israel and Britain of seeking to overthrow the clerically overseen government.

State TV reported that six people were killed during an attack on a police station in the town of Qahdarijan in clashes sparked by rioters who tried to steal guns from the station.

TV reports also said an 11-year-old boy and a 20-year-old man were killed in the town of Khomeinishahr, while a member of Iran’s paramilitary Revolutionary Guard was killed in the town of Najafabad.

It said all three were shot by hunting rifles, which are common in the Iranian countryside.

The towns are all in Iran’s central Isfahan province, some 215 miles south of Tehran.

Protests in Tehran
Protests in Tehran (Ebrahim Noroozi/AP)

The semi-official Mehr news agency said an assailant using a hunting rifle killed a policeman and wounded three others in Najafabad.

President Hassan Rouhani has acknowledged the public’s anger over the flagging economy, which has benefited from his signature 2015 nuclear deal with world powers, but not in a way that has brought immediate gains for most Iranians.

Mr Rouhani and others have warned that the government will crack down on those it considers law breakers. None of the protest rallies have received permission from the Interior Ministry, making them illegal.

US President Donald Trump on Tuesday wrote on Twitter that “the people of Iran are finally acting against the brutal and corrupt Iranian regime”.

It is unclear what effect his tweets is having on the protests.

Some have shared them online, but many in Iran distrust him because he has refused to recertify the 2015 nuclear deal and his travel bans have blocked Iranians from getting US visas.

Iran’s Foreign Ministry spokesman Bahram Ghasemi urged the US president to stop tweeting and focus on his own country’s problems.

“It is better for him to try to address US internal issues like the murder of scores killed on a daily basis in the United States during armed clashes and shootings, as well as millions of the homeless and hungry people in the country,” Mr Ghasemi said, according to the state-run IRNA news agency.

In Tehran, 450 protesters have been arrested in the last three days, the semi-official ILNA news agency reported on Tuesday.

ILNA quoted Ali Asghar Nasserbakht, a deputy governor of Tehran, as saying security forces arrested 200 protesters on Saturday, 150 on Sunday and 100 on Monday.