Clashes on Sunday between U.S. invaders and members of Al Mehdi army led by Iraqís Shia influential cleric Moqtada Al Sadr, left at least 18 dead at Baghdad mosque, Iraqi sources reported.
U.S. military said itís currently investigating the reports, which came from Iraqi police, medical sources as well as Al Sadr aides.
Those killed were worshipping at the time, according to a spokesman for the Mehdi Army.
Al Sadr aide accused the U.S. of killing unarmed people at the mosque.
"The American forces went into Mustafa mosque at prayers and killed more than 20 worshippers," Hazim al-Araji told Reuters news agency, citing a larger death toll than the 18 medical sources said were killed in clashes with the occupation at the mosque.
Also Sunday, one mortar round hit near the house of Al Sadr home Sunday near the Imam Ali shrine, one of the most important holy places for Shia Islam in the holy city of Najaf, but the Shia leader wasnít hurt in the attack that injured a child and at least one guard, Sheik Sahib Al Amiri said.
The Shia cleric issued a statement calling for calm.
"I call upon all brothers to stay calm and I call upon the Iraqi army to protect the pilgrims as the Nawasib (militants) are aiming to attack Shias everyday," he said, referring to Wednesday's commemoration marking the death of the Prophet Muhammad (PBUH).
Najaf police chief described the incident as a "cowardly attack" aimed at dividing the Iraqi nation.
"But this will not happen," Maj. Gen. Abbas Mi'adal told reporters. "We are ready to confront any terrorist schemes and protect the pilgrims."
Iraqi security forces earlier found bodies of thirty beheaded men at a roadside near Mullah Eid, a village to the south-west of the Iraqi city of Baquba, security officials said.
A roadside bomb exploded Sunday morning in front of a school in the southeast Iraqi city of Basra, killing a 13-year-old student, Iraqi police said.
The blast in Basra, Iraq's second-largest city, 340 miles southeast of the Iraqi capital and close to the countryís border with Iran, took place at around 7:30 a.m. as children were arriving at the school- Iraqi school weeks run Sunday through Thursday.
In Baghdad, another explosion in front of a house in the central neighborhood of Karradah killed a woman and gravely injured three other civilians.
Three security contractors are in a serious condition from injuries sustained from a roadside bomb in north Baghdad, police said.
Just as early the U.S. president's lies justifying Iraq war were revealed, the war consequences became clear at the initial stages of war.
Widespread violence and emergence of gangs endangering the lives of the Iraqi citizens, not to mention the deliberate killing of civilians at the hands of the occupation soldiers, all started with the early weeks of the invasion in March 2003.
The Bush administration was never concerned about the mess caused by the political vacuum it created in Iraq and the impact it would have on the Iraqi nation.
Washington was never willing to commit the resources necessary to secure the country it invaded to oust its leader and grab it oil wealth.