Baghdad ? A string of bombs killed 35 children and wounded scores of others as U.S. troops handed out candy Thursday at a government-sponsored celebration to inaugurate a sewage plant. It was the largest death toll of children in any insurgent attack since the start of the Iraq conflict.

Grief-stricken mothers wailed over their children’s bloodied corpses, as relatives collected body parts from the street for burial and a boy picked up the damaged bicycle of his dead brother.

The wounded were rushed to Yarmouk Hospital, where angry relatives screamed for attention from the overwhelmed doctors, many of whom wore uniforms covered in blood. One woman tore at her hair before pulling back the sheet covering her dead brother and kissing his body.

The bombings in Baghdad’s western al-Amel neighborhood — at least two of which were in cars — came amid a series of savage attacks that killed at least 51 people and wounded 230 nationwide. At least one U.S. soldier was among the dead and 13 were wounded.

Early today, U.S. and Iraqi forces launched a major attack against the insurgent stronghold of Samarra, securing government and police buildings in the city, the U.S. command said.

The offensive came in response to “repeated and unprovoked attacks by anti-Iraqi forces” against Iraqi and coalition forces, the military said in a statement. Its aim was to kill or capture insurgents in the city, 60 miles north of Baghdad.

The statement provided no further details of the fighting. A report by CNN said 2,000 rebels were believed to be holed up in the city and that tanks and jets were being used as troops took the city “sector by sector.”

Jordanian terror mastermind Abu Musab al-Zarqawi’s Tawhid and Jihad group claimed responsibility Thursday for bloody attacks in Baghdad, according to a statement posted on a militant Web site.

The authenticity of the statement could not be verified, and it was unclear whether the three “heroic operations” it cites — attacks on a government complex and “a convoy of invading forces” — included the bombs that killed the children.

Two injured children are placed on the same bed because of lack of available beds at Yarmouk Hospital after two car bombs and a roadside bomb went off in succession at the al-Amel neighborhood of Baghdad, Iraq. At least 42 were killed, of which 35 were children, and at least 131 wounded in the attack.

‘Spreading horror’

Early reports said a U.S. convoy was passing by the celebration when the attack occurred. The U.S. military said later that American soldiers were taking part in the celebration but that no convoy was passing through the area.

Deputy Interior Minister Gen. Hussein Ali Kamal said intense military pressure on insurgents holed up in Fallujah, west of Baghdad, was forcing them to turn their bombs on the capital. He said the day’s attacks were “definitely coordinated.”

“They are killing citizens and spreading horror. They have no aims except killing as many Iraqis as they can,” Kamal said. American jets, tanks and artillery units have repeatedly targeted al-Zarqawi’s followers in Fallujah, as coalition forces seek to assert control over insurgent enclaves ahead of elections slated for January.

After the bombings at the government-sponsored celebration in the capital, Yarmouk Hospital received 42 bodies, including 35 children, said Dr. Azhar Zeid. The hospital also treated 131 wounded, 72 of them under age 14, added Dr. Mohammed Salaheddin.

‘Come here, come here’

Some of the children, who are near the end of a nationwide school vacation, said they were attracted to the neighborhood celebration by American soldiers handing out candy.

“The Americans called us. They told us: ‘Come here, come here,’ asking us if we wanted sweets. We went beside them, then a car exploded,” said 12-year-old Abdel Rahman Dawoud, lying naked in a hospital bed with shrapnel embedded all over his body.

Interior Ministry spokesman Col. Adnan Abdul-Rahman said a car bomb and an explosive device planted in the road detonated in quick succession at the site of the celebration. Soon afterward, a second car bomb plowed into the area as crowds rushed to help the wounded, he said.

Maj. Phil Smith, spokesman for the U.S. 1st Cavalry Division, said all three blasts were caused by car bombs, the first two targeting the celebration and the third aimed at an Iraqi National Guard checkpoint about a mile away. Ten U.S. soldiers were wounded, he said.

Neither official would confirm whether suicide attackers were involved, and the conflicting accounts could not immediately be reconciled.

“This attack was carried out by evil people who do not want the Iraqis to celebrate and don’t want (reconstruction) projects in Iraq,” National Guard Lt. Ahmad Saad said at the scene.

Attacks elsewhere

In other incidents Thursday:

• A suicide attacker detonated a vehicle packed with explosives in front of a government complex in the Abu Ghraib area, on the western outskirts of Baghdad. The bombing killed a U.S. soldier and two Iraqi policeman and wounded more than 60 people, including three American soldiers.
• On Baghdad’s outskirts, an insurgent-fired rocket killed one soldier and wounded seven, the U.S. military said. No further information was disclosed.
• In the northern city of Tal Afar, a car bomb targeting the police chief killed at least four people and wounded 19. The police chief escaped unharmed.
• In Kirkuk, the mayor’s chief bodyguard was gunned down in his vehicle.
• U.S. forces struck a suspected militant safe house in Fallujah. Hospital officials said at least four Iraqis were killed and eight wounded.