Many thousands of Iranians have gathered in central Tehran square for a rally against Israel and in support of the Lebanese militant group Hezbollah.
The crowd shouted slogans and waved placards
The Iranian parliamentary speaker addressed the crowds, warning Israel that no part of its territory is safe.
Protesters waved Hezbollah flags and carried posters of its leader and shouted "death to Israel".
Iran backs Hezbollah, which seized two Israeli soldiers last week sparking Israeli air strikes across Lebanon.
Hezbollah has responded to the Israeli offensive by firing rockets into Israeli towns from Lebanon's southern border.
Iranian speaker Gholam Ali Haddad Adel said Israel should "flee occupied Palestine".
"The Americans should know that as long as this filthy tumour lies in the body of the Islamic world, Muslims will not stop hating America," he said.
Mr Haddad Adel said Israeli towns were within range of "the brave children of Lebanon".
Gholam Ali Haddad Ade told Israel to "flee Palestine"
He also called on Muslims whose governments had criticised Hezbollah to rise up against their leaders - a reference to many Gulf states, Jordan and Saudi Arabia.
The crowds pelted a star of David symbol with stones and tomatoes. President George Bush was portrayed in posters as Hitler, Osama Bin Laden and the devil.
Israel has accused Iran of providing missiles to Hezbollah, although Iran denies this.
The BBC's Iranian analyst Sadeq Saba says the fighting in Lebanon is benefiting Tehran by distracting international attention from its controversial nuclear programme.
But our correspondent says the Iranian government has adopted a cautious approach and most analysts say the country does not want to enter the crisis directly, unless Israel attacks Syria or Iran itself.
More than 200 Lebanese citizens have been killed since Israel launched air strikes last Wednesday following the capture of two Israeli soldiers by militant group Hezbollah.
Twenty-four Israelis have died in the violence - 12 as a result of Hezbollah rocket attacks.