NASIRIYAH, Iraq -- A suicide bomber blew up a truck packed with explosives at an Italian paramilitary base Wednesday, killing at least 26 people. The United States struck at the Iraqi insurgency hours later, destroying a warehouse in Baghdad and chasing attackers who were seen firing mortars.
The Nasiriyah attack was the deadliest against an American ally since the occupation began and appeared to send a message that international groups are not safe anywhere in Iraq. It came on the same day the chief U.S. administrator for Iraq went to the White House to put forth proposals on transferring more authority to the Iraqis.
Col. Gianfranco Scalas said 18 Italians were killed: 12 Carabinieri paramilitary police, four soldiers, a civilian working at the base and a documentary filmmaker. A spokesman for the U.S.-led coalition said at least eight Iraqis also died. The bomber -- whose nationality was not known -- also died.
The blast wounded 79 people, 20 of them Italians, hospital sources and Italian officials said.
Italians were stunned by their nation's single worst military loss since World War II and its first in the Iraq campaign.
Mission to continue
Italian Premier Silvio Berlusconi pledged that Italy's mission in Iraq would not be derailed. Opposition leaders who opposed the deployment to postwar Iraq called on the government to withdraw the contingent.
Jalal Talabani, the head of the Iraqi Governing Council, called the slain Italians "martyrs of the fight for the freedom of Iraq."
There were conflicting accounts of the attack, which took place about 10:40 a.m. at a three-story building used by the Carabinieri's multinational specialist unit in Nasiriyah, 180 miles southeast of Baghdad.
Witnesses said the decoy car ran a roadblock in front of a square where the Italian barracks was located. Guards opened fire but as the vehicle sped away, the fuel tanker approached from the opposite direction and rammed into the gate of the building before exploding.
It was the 13th vehicle bombing in Iraq since Aug. 7, when a car exploded at the Jordanian Embassy in Baghdad, killing at least 19 people.
Portugal said it was changing plans to deploy 128 elite police officers to Iraq because of the attack. The contingent will go to Basra instead of Nasiriyah.
After nightfall in Baghdad, forces from the 1st Armored Division attacked a warehouse used by insurgents, setting off explosions that reverberated through the capital.
"The facility is a known meeting, planning, storage and rendezvous point for belligerent elements currently conducting attacks on coalition forces and infrastructure," the Pentagon said.
The mission was part of "Operation Iron Hammer," a new "get tough" policy for confronting insurgents.
Also Wednesday, troops in Baghdad spotted attackers firing mortars, a statement from the 1st Armored Division said. The attackers fled in a van, making several stops as they tried to evade pursuing ground troops.
An Apache helicopter gunship discovered the van heading out of the city near the Abu Ghraib suburb and opened fire, disabling the vehicle and killing two of the occupants, the statement said. Three occupants were wounded and five others were captured.
Troops searching the first place where the van stopped found an 82mm mortar launch tube, the statement said. Searches of the other sites continued.
President Bush met with his top foreign advisers and chief Iraq administrator L. Paul Bremer on Wednesday to discuss the deteriorating security situation and the impasse in drafting an Iraqi constitution.
"We have said from the outset that we wanted to transfer authority to the Iraqis as quickly as they were able to assume it and that is what we have done," Bremer said in Washington. "We have been moving forward on ways to continue to transfer authority to the Iraqis as they are ready for it."
A CIA report warned that Iraqis were losing faith in the U.S.-led forces, which is increasing support for the insurgents.
Secretary of State Colin Powell said there will be "ups and downs in attitudes and feelings. We will remain long enough to make sure the Iraqi people have the opportunity to put in place a government that is democratic."
Bremer's talks came as Iraqi insurgents have stepped up their attacks and U.S. and Iraqi leaders appeared to be making no progress in drafting a new constitution for Iraq.
White House press secretary Scott McClellan said the Bush administration expressed its condolences to Italy for "standing with the United States and the rest of the coalition in the war against terrorism."
Italy has sent about 2,300 troops to help rebuild Iraq. About 340 Carabinieri are based in Nasiriyah, along with 110 Romanians. No Romanians were reported wounded in Wednesday's attack.
Carabinieri are paramilitary police under the Defense Ministry, and have serve in Afghanistan and the Balkans.
In other developments:
--U.S. troops in Baghdad on Wednesday accidentally fired on a car carrying Mohammed Bahr al-Uloun, a member of the Iraqi Governing Council, wounding his driver.
--U.S. paratroopers killed six attackers and wounded four others in a shootout Tuesday near the hospital run by the Jordanian government near Fallujah, the 82nd Airborne Division said.
The shootout began when troops were fired on with automatic weapons from a vehicle stopped near the hospital. When the soldiers returned fire, the attackers tried to flee to a second car, the military said.
--Assailants fired rocket-propelled grenades and small arms at an American military compound in Mosul on Wednesday, killing an Iraqi paramilitary guard.
--An American soldier was killed when a roadside bomb exploded near a patrol by the town of Taji northwest of Baghdad, and another died of wounds suffered in a roadside bombing in Baghdad.
The deaths bring to 153 the number of U.S. soldiers killed by hostile fire since Bush declared an end to active combat May 1.