Iranian President Mahmoud Ahmadinejad blamed the United States and Israel on Thursday for the destruction of a Shiite shrine's golden dome in Iraq, saying it was the work of "defeated Zionists and occupiers."

Speaking to a crowd of thousands on a tour of southwestern Iran, the president referred to the destruction of the Askariya mosque dome in Samarra on Wednesday, which the Iraqi government has blamed on insurgents.

"They invade the shrine and bomb there because they oppose God and justice," Ahmadinejad said, alluding to the U.S.-led multinational forces in Iraq.

"These passive activities are the acts of a group of defeated Zionists and occupiers who intended to hit our emotions," he said in a speech that was broadcast on state television. Addressing the United States, he added: "You have to know that such an act will not save you from the anger of Muslim nations."

The bombing set off a string of sectarian attacks in Iraq in which militiamen attacked Sunni mosques and at least 19 people were killed. No group claimed responsibility for the bombing, but suspicion fell on Sunni extremist groups.

On Wednesday, President Bush urged restraint among rival religious factions in Iraq and pledged American help to restore the shrine.

"The terrorists in Iraq have again proven that they are enemies of all faiths and of all humanity," the president said in a written statement. "The world must stand united against them, and steadfast behind the people of Iraq."

Arab leaders also condemned the attack Wednesday. The Askariya shrine contains the tombs of two revered Shiite imams descended from the Prophet Muhammad.

Jordan's King Abdullah II called the bombing "heinous." Lebanese Prime Minister Fuad Saniora said it was aimed at "splitting Shiite and Sunni Muslims." And Kuwait's new emir, Sheik Sabah Al Ahmed Al Sabah, said those who target holy places and kill innocent people "are as far as can be from the teachings of Islam."

But some Islamic clerics and the Lebanese Hezbollah organization blamed the United States.

"We cannot imagine that the Iraqi Sunnis did this," said the influential Sunni cleric Sheik Youssef al-Qaradawi, an Egyptian who lives in Qatar. "No one benefits from such acts other than the U.S. occupation and the lurking Zionist enemy."

Radical Iraqi Shiite cleric Muqtada al-Sadr, who cut short a visit to Lebanon after the blast, said blame must be laid either with the Americans or the Iraqi government.

"If responsibility is not in the hands of the Iraqi government, then I consider the responsibility for this event lies with the occupation forces which should either leave immediately or according to a timetable," al-Sadr said in Syria on his way back to Iraq.

The Iraqi Interior Ministry said four men, one wearing a military uniform and three in black, entered the Askariya mosque early Wednesday and detonated two bombs, one of which collapsed the dome.