JERUSALEM: Israel's intelligence minister on Monday voiced encouragement for Iranian anti-government protesters but added that Israeli policy was not to get involved in Tehran's internal affairs.

Four days of demonstrations in Iran have posed the boldest challenge to its clerical leadership since pro-reform unrest in 2009. At least four people have been killed as some confrontations with police turned violent.

"I can only wish success to the Iranian people in the struggle for freedom and democracy," Israeli Intelligence Minister Israel Katz said in an Army Radio interview.

"If the people succeed in achieving freedom and democracy, many of the threats on Israel and the entire region today will disappear."

Israel has long voiced alarm over the Shi'ite power's nuclear programme and its support for Islamist guerrillas in Lebanon and the Palestinian territories - concerns shared by Sunni Arab states.

Asked why Israeli Prime Minister Benjamin Netanyahu was not following U.S. President Donald Trump's example in offering more open endorsement for the protesters, Katz said: "Israel has undertaken not to get involved in this internal affair".

Trump's tough approach to Tehran, which has included the threat of U.S. sanctions, had disrupted the Iranian government's "illusion of economic betterment", he said.

On Sunday, an Iranian official blamed "foreign agents" for a clash in which two protesters were killed.

Katz dismissed such allegations as standard fare from "a mendacious and propagandistic regime".-Reuters