Iran has seen its largest anti-government protests since the disputed presidential election in 2009, with thousands taking to the streets in several cities in recent days.
Israeli Prime Minister Benjamin Netanyahu wished success to Iranian anti-government protesters on January 1but emphasised that Israel was not involved in Tehran's internal affairs.
Since Thursday, tens of thousands of people have taken to the streets across Iran, alarming the government and posing the boldest challenge to its clerical leadership since pro-reform unrest in 2009.
Ten people were killed during protests on Sunday, state television reported, as unsigned statements posted on social media sites called for new demonstrations in the capital Tehran and 50 other cities.
Netanyahu said that any suggestion Israel was involved in the Iran protests was preposterous. "It's not only false - it's laughable," he said. He added that he wished success to Iranians seeking justice and freedom.
On Sunday, an Iranian official blamed "foreign agents" for a clash in which two protesters were killed.
However, ISNA news agency quoted Iranian President Hassan Rouhani as contradicting the usual conspiracy theories that blame Western powers and Israel for Iran's woes, stressing the need to get to the root causes of the problem.
Demonstrators say they are angry over corruption and economic hardship in a country where youth unemployment reached 28.8 percent last year.