Israel's Mossad spy agency issued a direct call urging Iranians to press on with protests, saying it was supporting them "on the ground" as demonstrations spread in capital Tehran and other Iranian cities.
"Go out into the streets together. The time has come. We are with you," Mossad wrote in a post on its Farsi-language X account, Israel's army radio reported on Wednesday.
"Not just from a distance or through words. We are also with you on the ground."
Protests that began on Sunday with Tehran shopkeepers rallying against Iran's worsening economy have spread to other cities, drawing in students as well.
The Iranian rial has dropped against the US dollar and other world currencies, forcing up import prices and hurting retail traders.
The appeal also came after talks this week between Israeli Prime Minister Benjamin Netanyahu and US President Donald Trump, following which Trump warned Iran of fresh strikes if it rebuilt its nuclear or ballistic missile programs.
Arch-foes Iran and Israel fought a 12-day war earlier this year, after Israel launched a wave of strikes on Iranian nuclear facilities as well as residential areas, saying it aimed to cripple the country's atomic research and ballistic missile capabilities.
Iran responded with drone and missile attacks on Israel. Later in the conflict, the United States joined Israel in briefly targeting Iranian nuclear sites before a ceasefire was declared.
Iran, which does not recognize Israel, has long accused it of conducting sabotage operations against its nuclear facilities and assassinating its scientists.
It also backs militant groups around the region as part of its so-called "Axis of Resistance", including Lebanon's Hezbollah and the Palestinian movement Hamas, both of which Israel has fought major wars with Israel in the past two years.
Former Hamas leader Ismail Haniyeh was assassinated in Tehran in July 2024 in an attack attributed to Israel.