BAGHDAD Iraq's government and police said a bomb blast near a soccer field in the western city of Ramadi on Tuesday killed 18 people, mostly children, but the U.S. military said it was unaware of such an attack.
The United States said it would attend two conferences planned by Prime Minister Nuri al-Maliki's government that were designed to help stabilize Iraq and may involve contact with Iran and Syria, nations Washington has been reluctant to engage.
"(Maliki) believes, and President Bush and I agree, that success in Iraq requires the positive support of Iraq's neighbors," said U.S. Secretary of State Condoleezza Rice. The conferences are expected to be held in March and April.
The U.S. military said its soldiers had carried out a controlled explosion in Ramadi, near a soccer field, that wounded 30 people, including nine children.
"I can't imagine there would be another attack involving children without our people knowing," said Major Jeff Pool, a spokesman for U.S. forces in western Anbar province. The wounded had cuts and bruises, he said.
The offices of Maliki and President Jalal Talabani issued statements condemning the blast that they said killed 18 people.
Maliki's office said the dead included 12 children, while Talabani's office said all 18 were children.
The U.S. military often carries out controlled explosions in Iraq to destroy captured weapons or unexploded bombs.
Pool said the controlled blast in Ramadi was "stronger than we had expected". He said it was carried out in a courtyard where bags of explosives had been found. Windows in a nearby building were blown out, causing the wounds.
U.S. forces helped evacuate the wounded, said Pool.
Tribal leader Hamid Farhan al-Hays from Ramadi said on Iraqiya state TV Sunni Arab-led al Qaeda was behind the blast.
Sunni tribal elders are involved in an escalating power struggle with al Qaeda for control of the vast desert province of Anbar that is at the heart of the Sunni insurgency in Iraq. Ramadi is the capital of Anbar.
Iraq's minority Sunni community was dominant under Saddam Hussein but Shi'ite Muslim Maliki now heads the government.
A truck bomb near a Sunni mosque in Ramadi killed 52 people on Saturday, a day after the mosque's imam had made a speech criticizing al Qaeda, which is entrenched in the area.
On Monday, a suicide bomber blew up an ambulance at an Iraqi police station near Ramadi, killing 14 people.
Seeking to damp down the violence gripping Iraq, U.S. and Iraqi forces are stepping up a new security crackdown in Baghdad. Washington is also sending extra troops to Anbar.
The first conference planned by Baghdad in March is expected to gather ambassadors from Iraq's neighbors as well as the permanent members of the U.N. Security Council -- Britain, China, France, Russia and the United States.
Rice said in Washington the second meeting could take place in the first half of April and would draw ministers from those countries as well as the Group of Eight leading industrialized nations, which include Canada, Germany, Japan and Italy.
In December, a report by the bipartisan U.S. Iraq Study Group recommended Washington hold direct talks with Damascus and Tehran to persuade them to help stem violence in Iraq. President Bush reacted coolly.
U.S. officials accuse Iran of fanning violence in Iraq. They say Syria allows foreign fighters to cross its long, porous border with Iraq to join those fighting the U.S.-backed government. Both countries deny the accusations.
The U.S. embassy in Baghdad said Ambassador Zalmay Khalilzad would attend the planned mid-March talks. A British embassy spokeswoman said Britain would also take part.
The March meeting would be a chance for Western and regional powers to try to bridge some of their differences over Iraq, Iraqi Foreign Minister Hoshyar Zebari said.
"Our hope is that this will be an ice-breaking attempt for maybe holding other meetings in the future. We want Iraq, instead of being a divisive issue, to be a unifying issue."
(Additional reporting by Mariam Karouny in Beirut)