An attack on a Shi'ite Muslim shrine in Iraq has sparked a wave of violence between Shi'ite and Sunni Muslims. More than 130 people, most of them Sunnis, have been killed since the attack Wednesday. The incident puts Iraq's new, but fragile, democracy at risk.

Iraqis rally in reaction to the shrine explosion in Samarra, in the holy Shiite city of Najaf, 160 kilometers (100 miles) south of Baghdad, Wednesday, Feb. 22, 2006

Reprisal attacks erupted across Iraq in response to the bombing that wrecked the Askriya shrine Wednesday in the city of Samarra. The violence is threatening to wreck Iraq's fragile political process.

Security forces in Baghdad were placed on high alert as scores of Sunni mosques were under attack in retaliation for the bombing of the shrine, which is sacred to Shi'ites. Sunni clerics were abducted and killed and three Iraqi journalists for al-Arabiya television were also killed.

Thousands of demonstrators marched through parts of Baghdad, Karbala, Kut, Tal Afar, and the Shi'ite holy city of Najaf to protest the shrine attack.

Some Sunni and Shi'ite leaders appealed for calm.

Khalif Ai-Ilyan, head of the Iraqi National Dialogue - a Sunni party - warned that the attack was designed to spark a sectarian civil war.

On the other side of the divide, a representative of Shi'ite cleric Mahmoud al-Sarki said the attack was motivated not by religion, but by politics.

George W. Bush

In Washington, President Bush also condemned the attack as a political act designed to split Shi'ites and Sunnis.

"The act was an evil act," said President Bush. "The destruction of a holy site is a political act intending to create strife. So I am pleased with the voices of reason that have spoken out."

But some Iraqi religious leaders were not mollified. The firebrand Shi'ite cleric Moqtada al-Sadr accused the United States and the fledgling Iraqi government of failing to protect the 1,200-year-old shrine.

On the other side of the religious divide, a spokesman for the Sunni Association of Muslim Scholars blamed the escalating violence on the country's top Shi'ite cleric, Grand Ayatollah Ali al-Sistani, and other Shiite religious leaders. Criticism of al-Sistani, a revered figure, has been unheard of until now.

Jack Straw

Although no one has claimed responsibility for the attack, British Foreign Secretary Jack Straw said suspicion fell on al-Qaida in Iraq.

The bombing threatens to unravel Iraq's still-fragile political structure. Talks on the formation of a new government are still under way among Shi'ites, Sunnis, and Kurds.

President Jalal Talibani called a meeting to discuss the growing crisis. Some Sunni leaders attended, but others did not and are threatening to walk out of the political process altogether.