Tehran - Iran on Monday held a protest rally against Israel's raids on the Gaza Strip and a clergy group recruited volunteers to aid the Palestinians in their fight against Israel.

Tens of thousands took part in the state-organized demonstration in the capital Tehran, shouting "Death to Israel" and "Death to America," and burned the Israeli flag.

The demonstrators called on the Arab world and international organizations to break their silence and initiate steps for an immediate end of the killings.

Iran's supreme leader Ayatollah Ali Khamenei declared Monday a day of public mourning throughout the country.

The Fars news agency reported that a clergy group had started internet registration for recruiting volunteers to fight alongside Palestinians against Israel.

The Combatant Clergy Society claimed that so far over 1,000 volunteers have registered for fighting against Israel but did not say how the volunteers were to reach the Gaza Strip.

The Iranian government has constantly distanced itself from such initiatives.

Ayatollah Khamenei on Sunday called on Arab states to stop what he called "Zionist (Israeli) wolves" from committing further crimes against Palestinians in Gaza.

The Ayatollah also condemned the United States and President George W Bush who, he said, "has just made his war crime records thicker."

President Mahmoud Ahmadinejad rebuked Israel and urged immediate action to end the Gaza crisis.

Iran on Sunday sent a plane with medicine and food to Gaza and a second plane was to be dispatched on Monday. (dpa)