Baghdad, Iraq - Insurgents have assassinated three clerics in Baghdad in an escalating wave of violence that authorities fear is aimed at sparking civil war.
Al Qaeda's wing in Iraq also warned the country's Sunni Arabs to take no part in drafting a new constitution, in another sign militants are trying to fuel sectarian tensions.
Guerrillas shot two Shi'ite clerics in Baghdad on Tuesday. Mani Hassan, a member of a leading Shi'ite Islamist party, was killed outside his house, and Muwaffaq Mansour was ambushed in his car.
The body of Hassan Nuaimi, a member of the Sunni Muslim Clerics Association, was also found in Baghdad on Tuesday, a day after the group accused the Shi'ite-dominated government of state terrorism and ignoring the killings of Sunnis.
The violence raged as Iranian Foreign Minister Kamal Kharrazi was set to meet Iraqi leaders during a trip to Baghdad.
Kharrazi is the most senior Iranian official to visit Iraq since the fall of
Saddam Hussein two years ago.
Some Sunni Arabs, suspicious of Iran after the Iran-Iraq war, are worried that the Shi'ite Islamists' victory in Jan. 30 elections will give Tehran a chance to influence Iraqi affairs.
Islamist Shi'ites and Kurds, long oppressed under Saddam Hussein, won control of parliament in the polls and the Sunni Arab minority that dominated during Saddam's rule was sidelined.
Guerrilla attacks have killed more than 400 people since Iraq's new government was announced three weeks ago. Most of the dead were killed by a surge in suicide bombings.
In another assassination in Baghdad, guerrillas killed Alaidin al-Ubaidi, an engineer working for the Commission on Public Integrity, which probes corruption in Iraq.
On Sunday, gunmen in eastern Baghdad killed Qasim al-Gharrawi, a cleric who was the local representative of Iraq's most revered Shi'ite leader, Ayatollah Ali al-Sistani.
AL QAEDA WARNING
In a bid to defuse the Sunni-led insurgency, Shi'ite and Kurdish leaders have pledged to give Sunni Arabs an important role in politics despite their low representation in parliament.
Jaafari said on Monday after a meeting with Sistani that the moderate Shi'ite spiritual leader had urged a key role for Sunni Arabs in drafting the constitution.
Condoleezza Rice also said during a visit to Iraq on Sunday that Sunni Arabs had to be included.
But the al Qaeda network in Iraq, led by Jordanian militant Abu Musab al-Zarqawi, said in an Internet statement that any Sunni who responded to Rice's call for greater Sunni Arab participation would be an infidel.
"The Crusaders' hag came to sully the land of the caliphate ... and wants the participation of apostates and secularists claiming to be Sunnis," the statement said.
"Would anyone draft the constitution other than those who do not believe in God's book? Our Sunni faith stipulates that the sword and bullets be the only dialogue between us and the worshippers of the cross."
So far majority Shi'ites have largely heeded calls by Sistani and other moderate clerics to show restraint.
In a worrying development, some victims of recent execution-style killings have been Sunnis. Since Saturday, authorities have found the bodies of 49 people who had been tied up, killed and their bodies dumped.
The bodies of three Iraqi soldiers, including one who was beheaded, were found on Tuesday in the town of Qaim, near the Syrian border, an army source said.
On Tuesday, a U.S. soldier was killed and another wounded when a roadside bomb hit their combat patrol just south of Saddam's hometown of Tikrit, the U.S. military said.
Gunmen killed four Iraqi soldiers and wounded three in fighting outside a power plant in the southern Iraqi town of Mussayib on Tuesday, army sources said.
(Additional reporting by Ahmed Seif in Baghdad, Sami al-Jumaili in Kerbala and Fadel al-Badrani in Falluja)