A large explosion today destroyed the golden dome of one of Iraq's most famous Shia religious shrines, sending protesters pouring into the streets.
It was the third major attack against Shia targets in as many days.
No group claimed responsibility for the early morning attack in which gunmen burst into the Askariya shrine in Samarra, 60 miles north of Baghdad and used explosives to bring down its 100-year-old gilded dome, among the biggest in the Muslim world. The shrine contains the tombs of two revered Shia imams, both descendants of the Prophet Muhammad, and is among Iraq's most sacred sites for Shia Muslims.
The apparently bloodless attack on the Golden Mosque provoked more violence than Sunni rebel attacks that have killed thousands and the Shi'ite-led government and religious leaders urged calm. The attack on such a major religious shrine threatened to enflame sectarian passions at a time when talks among Shia, Sunnis and Kurds on a new government have bogged down.
Three Sunni clerics were among six people killed, police said, at 27 Sunni mosques in Baghdad attacked by militants. Much damage was minor but at least two mosques were burned out. There were sectarian clashes in other cities.
In Baghdad, National Security Adviser Mouwafak al-Rubaie blamed religious zealots such as al-Qaeda and Ansar al-Sunnah, telling Al Arabiya television that the attack was an attempt "to pull Iraq toward civil war".
Prime Minister Ibrahim al-Jaafari, a Shi'ite, declared three days of mourning and called for Muslim unity.
President Jalal Talabani, an ethnic Kurd, accused the attackers of trying to derail negotiations on a national unity coalition: "We must ... work together against ... the danger of civil war," he said in a televised address to the nation.
The country's most revered Shia cleric, Grand Ayatollah Ali al-Sistani, sent instructions to his followers forbidding attacks on Sunni mosques, especially the major ones in Baghdad. He called seven days of mourning, his aides said.
Thousands of people marched in Shi'ite towns across the country and through the capital, condemning the Samarra attack. Black-clad militiamen of the Mehdi Army, loyal to Shi'ite cleric Moqtada al-Sadr, were out in force in Shi'ite strongholds like Sadr City in Baghdad and the southern city of Samawa. In Samarra, thousands of demonstrators gathered near the shrine, waving Iraqi flags, Shia religious banners and copies of the Koran.
The United States, anxious to calm passions and bring its troops home, has pressured Shi'ite leaders to bring Sunnis into government after the rebellious minority took part in an election in December; a top Shi'ite politician accused the US envoy of encouraging the bombers by supporting Sunni demands.
Iran claimed the attack on the shrine was orchestrated by Israel and US-led foreign forces hoping to promote sectarian strife in Iraq.
Supreme Leader Ayatollah Ali Khamenei, who has the last word on all state matters in the Islamic Republic, urged Shi'ites not to take revenge on Sunni Muslims for the attack.
"This is a political crime and its origins should be found in the intelligence organisations of the occupiers of Iraq and the Zionists," Ayatollah Khamenei said in a statement read out on state television.
Agencies
.