However, some warned Saddam's death could worsen the violence and civil strife in Iraq.

State-run television in Iran called the former Iraqi leader an "enforcer of the most horrendous crimes against humanity." Iran fought an eight-year war with Saddam's Iraq in the 1980s.

President Mahmoud Ahmadinejad said he hoped Saddam's hanging would bring stability to Iraq, though he told Iraqi President Jalal Talabani by telephone the execution prevented the exposure of atrocities the former dictator committed during his rule, state-run television reported.

In Washington, President Bush said Saddam received "the kind of justice he denied the victims of his brutal regime."

"Bringing Saddam Hussein to justice will not end the violence in Iraq, but it is an important milestone on Iraq's course to becoming a democracy that can govern, sustain and defend itself, and be an ally in the war on terror," Bush said in a statement.

While there was little official reaction from the Arab world, many Muslims criticized the timing of the execution just hours before the start of the most important holiday of the Islamic calendar, Eid al-Adha.

Egypt's Foreign Ministry said Iraqi authorities hung Saddam "without considering the Muslims' feelings or respecting the sanctity of this day that represents an occasion for forgiveness and absolution," according to the official news agency, MENA.

In Jordan, a leading member of the Muslim Brotherhood party, Jamil Abu-Bakr, said executing Saddam at the start of the holiday was an attempt "to harm the Muslim nation."

Libya, meanwhile, announced a three-day period of national mourning, lowered its flags to half mast and canceled its Eid celebrations.

In the Palestinian territories, where Saddam was considered a generous patron, his execution was met with sadness. A "house of condolences" - decorated with Iraqi flags and pictures of Saddam - was set up in Bethlehem as a place for people to mourn.

News of Saddam's death quickly reached Muslims participating in this year's hajj in Saudi Arabia. The pilgrims on Saturday performed a ritual stoning of the devil.

"Today we were stoning the devil, but we were also stoning Saddam," said Sayed Hassan Moussawi, an Iraqi Shiite cleric. "Everyone here is so happy. He killed so many men, women and children and he tormented Iraq's Shiites."

Elsewhere in the world, Saddam's execution was greeted with support in some corners but also with a degree of concern about the use of capital punishment, which is viewed with disdain in Europe.

In Italy, former Prime Minister Silvio Berlusconi, who had staunchly backed the US-led war in Iraq and sent Italian troops to fight, called the hanging "a step backward in Iraq's difficult road toward full democracy."

"The civilization in the name of which my country decided to send Italian soldiers into Iraq envisioned overcoming the death penalty, even for a bloody dictator like Saddam," he said.

British Foreign Secretary Margaret Beckett, like many others, tempered her criticism of the execution by saying Saddam had "now been held to account for at least some of the appalling crimes he committed against the Iraqi people."

The Vatican denounced the execution as "tragic," and Dutch Deputy Prime Minister Gerrit Zalm called it "barbaric."

Other countries feared the hanging would only spark more violence in Iraq.

"The country is being plunged into violence and is essentially on the edge of large-scale civil conflict," Russian Foreign Ministry spokesman Mikhail Kamynin said in Moscow. "The execution of Saddam Hussein may lead to the further aggravation of the military-political atmosphere and an increase in ethnic and religious tension."

Pakistan's Foreign Ministry said in a statement that the execution is "another poignant reminder of the violence that continues to grip Iraq. We hope that this event would not further exacerbate the security situation."