Trump calls for 'change' after at least 13 people killed in Iranian protests
Video report by ITV News Correspondent Romilly Weeks
Donald Trump has said it is "time for change" in Iran after at least 13 people were reportedly killed in nationwide protests in the country.
Iran's semi-official Mehr news agency reported a gunman killed a policeman and wounded three other officers during a protest gathering.
This is the first report of a police officer being killed during five days of protests and raises the total number of dead to 13.
Ten people were killed during clashes on Sunday night, while two demonstrators were killed at a protest in western Iran late on Saturday.
It was also reported that security forces had repelled "armed protesters" who tried to take over police stations and military bases.
Israel's prime minister Benjamin Netanyahu wished the protesters "success in their noble quest for freedom" and called them "brave" and "heroic".
Protests started in the northeastern city of Mashhad over economic issues and have spread to other cities, with hundreds of people arrested.
The protests are the largest to strike the Islamic Republic since those that followed the country's disputed 2009 presidential election.
The US president tweeted that "Iran is failing at every level", adding: "The great Iranian people have been repressed for many years. They are hungry for food and for freedom."
Iran's president Hassan Rouhani previously said people are free to protest but must not be allowed to make people "feel concerned about their lives and security".
"The government will definitely not tolerate those groups who are after the destruction of public property or disrupting the public order or spark riots in the society," he said.
Mr Trump previously tweeted about the protests on Sunday, saying: "The people are finally getting wise as to how their money and wealth is being stolen and squandered on terrorism."
He also tweeted that it looks like the Iranians "will not take it any longer" and added: "The USA is watching very closely for human rights violations!"
His initial tweets angered Iran's government, with a foreign ministry spokesman saying the "Iranian people give no credit to the deceitful and opportunist remarks of US officials or Mr Trump".
Mr Rouhani also criticised Mr Trump over his tweets about the protest, saying he "has forgotten that he had called Iranian people 'terrorists' a few months ago".
The protests were fanned in part by messages sent on the Telegram messaging app, which authorities blocked on Sunday along with the photo-sharing app Instagram, which is owned by tech giant Facebook.
Many in Iran are learning about the protests and sharing images of them through Telegram, a mobile phone messaging app popular among the country's 80 million people.
On Saturday, Telegram shut down one channel on the service over Iranian allegations it encouraged violence, something its moderator denied.