Hundreds of thousands of people took part in demonstrations around the world against the Iranian government on Saturday, following calls from the exiled son of the late shah for a "global day of action".

Addressing an estimated 250,000 people in Munich, Reza Pahlavi - who has called for the overthrow of Iran's Islamic regime - denounced a crackdown on recent protests there.

Munich, Los Angeles and Toronto saw the largest crowds, with smaller protests in cities including Tel Aviv, Lisbon, Sydney and London.

Activists say more than 6,000 people were killed after joining nationwide protests in Iran against the rising cost of living and the government. Thousands more deaths are being investigated.

Pahlavi told the crowd: "My first message is to our brave and fighting compatriots inside the country: know that you are not alone, and today the world stands with you in this struggle."

Criticising Iran's leadership, he said: "In contrast to this corrupt, repressive, child-killing regime, you represent a great culture and civilisation, and in a free Iran of tomorrow you will prove to the world what a great nation we are."

Pahlavi's daughter, Noor Pahlavi, addressed a crowd in Los Angeles. The BBC's US partner CBS News reported her as saying Iranians had "never been this close to freeing up themselves from this Islamic regime".

She called on US President Donald Trump to end ongoing nuclear talks with Iran's leadership, describing it as "negotiation with murderers".

On Friday, Trump told reporters a change in Iran's government would be the "best thing that could happen", though it was unclear whether his comments were in reference to Pahlavi, who is seeking a role in Iran.

Trump told news agency Reuters last month that Pahlavi seemed "very nice" but expressed uncertainty over whether he could muster enough support within Iran to eventually lead it.

In Toronto, where an estimated 350,000 joined a demonstration, participants told BBC Persian they were there to speak out on behalf of friends and family inside Iran.

Street protests broke out in Iran on 28 December, initially sparked by economic turmoil and fuelled by long-running discontent with the country's leaders.

Demonstrations spread to more than 100 cities and towns across all of Iran's provinces.

The US-based Human Rights Activists News Agency (HRANA) has confirmed the deaths of 6,872 protesters, including more than 150 children.

Iranian authorities have acknowledged that at least 3,000 people were killed, but have claimed some were members of the country's security forces.

Many demonstrators in Iran have chanted Pahlavi's name and called for his return to political leadership.

Groomed from birth to inherit the throne, Pahlavi was 18 when the 1979 Islamic Revolution swept away his father's monarchy.

Almost 50 years later, Pahlavi is once again seeking to shape his country's future.

But critics question whether his vision for Iran would ultimately lead to a democracy.