Meanwhile, violence continued across Iraq, with U.S. airstrikes in Fallujah, street battles and blasts in Baghdad, and clashes that killed British troops and Iraqi agents in Basra.
The two Italian aid workers, Simona Pari and Simona Torretta, were kidnapped in Baghdad on Sept. 7. A Muslim leader from Italy arrived in Baghdad Tuesday and met with a local Muslim association to press for their release.
The two women, both 29, were working for the aid agency "Un Ponte Per ... " ("A Bridge To ... "), and were involved in school and water projects.
Later, another Arab network Al-Arabiya, based in Dubai, confirmed the release. Al-Jazeera said the hand-over of the hostages took place in Baghdad.
Dozens of masked gunmen carrying automatic rifles and rocket-propelled grenades drove through the main streets of Samarra, north of Baghdad. They stopped some cars, asking occupants to hand over music tapes in exchange for those with recitations from the Muslim holy book, the Quran.
Samarra has been under insurgent control and a virtual "no-go" area for U.S. troops since May 30.
The Americans returned briefly Sept. 9 under a peace deal brokered by tribal leaders by which U.S. forces agreed to provide millions of dollars in reconstruction funds in exchange for an end to attacks on American and Iraqi troops.
The sporadic clashes around Haifa Street in Baghdad began early Tuesday and explosions could be heard around midday in the area, spokesman Col. Adnan Abdul-Rahman said. He said such low-intensity fighting has occurred on the street for the past three days.
Haifa Street, an insurgent stronghold, has been the scene of bloody car bomb attacks, raids and firefights in past weeks.
The roadside bomb on Karrada street damaged several vehicles and shattered windows, witnesses said. The target of the attack was not immediately clear. At least six other blasts were later heard in the capital.
Ambulances rushed to scene of the explosions and American troops cordoned off the area. Interior Ministry spokesman Col. Adnan Abdul-Rahman said three civilians were wounded.
The ministry had no immediate information on the other explosions that rocked the city at noontime.
In Fallujah, intelligence reports indicated that the militants targeted shortly after 4:00 a.m. were "rising" associates of al-Zarqawi and "planning attacks using foreign suicide bombers in vehicles rigged with explosives," the military said. The Jordanian-born militant has claimed responsibility for scores of suicide attacks and kidnappings across the country, as well as the recent beheading of two Americans
Late Monday, U.S. warplanes were spotted over the city and explosions were heard. Residents said they saw a plane firing rockets into the city, but U.S. Marine officers said only illumination rounds were fired.
Dr. Walid Thamer of the Fallujah General Hospital said at least three people were killed and nine wounded in the earlier attack. They arrived at the hospital around 1:00 a.m., he said. The conflicting accounts could not immediately be reconciled.
U.S. forces have not patrolled in Fallujah since ending a three-week siege of the city in April that left hundreds dead. Military commanders say an assault may be inevitable to restore authority there ahead of nationwide elections slated for January.
"I think we waited more than enough for Fallujah," the Iraqi leader said in an interview aired late Monday on the Arab television network Al-Arabiya. He indicated Iraqi security forces would be used in any operation against the city.