Violence hinders Iraqi political processes
Bombings kill 19 people in northern cities of the country
Shiite Arab cleric Hummam Hammoudi says the Sunni participation is welcome.
CNN's Jennifer Eccleston reports on Thursday's bombings.
Iraqi president says Saddam could stand trial within two months.
Some 40,000 Iraqi troops will participate in Operation Lightning.
BAGHDAD, Iraq (CNN) -- Sunni Arabs -- many of whom boycotted Iraq's elections -- began talks Thursday with members of the panel writing the country's new constitution, officials said.
The talks are part of an effort by the transitional National Assembly, dominated by Shiites and Kurds, to bring Sunni Arabs into the process of creating a new political culture.
"We welcome this participation," Shiite Arab cleric Hummam Hammoudi said in a CNN interview Wednesday. Sunnis "are accepting, willing and eager for this participation," he said.
Hammoudi heads the assembly's 55-member constitutional committee that has until August 15 to draft a document to be put before voters in October.
Sunni leaders met three hours Thursday with a seven-member subcommittee of the panel assigned the job of trying to bring their perspective into the drafting process, a Sunni official said. Another meeting is scheduled next week, he said.
The transitional government's task of creating a system representing all segments of the country's diverse population is made more difficult by having to deal daily with a violent insurgency led largely by Sunni Arabs.
On Thursday alone, three suicide car bombs within 45 minutes of one another killed at least 18 people and wounded 53 others in three restive cities north of Baghdad -- Tuz Khurmatu, Kirkuk and Baquba.
In the northern city of Mosul, a parked motorcycle rigged with explosives killed a police officer and wounded 16 others, a Nineveh provincial official said.
U.S. officials also reported Thursday that three American soldiers died the day before, including two in combat near Ramadi. Their deaths brought the total number of American troops killed in the war to 1,667.
One of the suicide bombings targeted a restaurant where security personnel often eat in Tuz Khurmatu, about 55 miles south of Kirkuk.
The attack killed 12 people and wounded 38, including several bodyguards of Iraqi Deputy Prime Minister Rowsch Shaways, a senior Iraqi official said.
In Kirkuk, about 40 minutes later, another suicide car bomb killed two children and wounded 11 civilians, said the commander of the Iraqi army guard in Kirkuk.
The attacker was trying to hit a U.S. diplomatic convoy entering the Arafa complex of the Northern Oil Co., but it missed and damaged three civilian cars, said Maj. Gen. Anwar Mohammed Amin.
In Baquba, a suicide car bomb hit a convoy carrying Hussein Alwan al-Thamimi, a deputy head of the city's governing council, police said. The attack killed al-Thamimi and three of his bodyguards, police said. Baquba is about 40 miles northeast of Baghdad.
Crafting a government
Among the subjects Sunni leaders discussed with the constitutional subcommittee Thursday was organizing conferences throughout the country on the constitution, said Ayad al-Samarraie, a spokesman for the Iraqi Islamic Party, a major Sunni Arab political group.
Another topic was making the constitution-writing committee more reflective of the population, al-Samarraie said.
Hammoudi said the government is intent on meeting the August 15 deadline.
"Any delay will give the impression that the process is not successful and erroneous," he said.
Among the prickly constitutional issues is federalism, an important concept in a diverse country like Iraq, where groups -- especially the Kurds -- value their autonomy.
Another key issue, Hammoudi said, is how to address the role of Islam in a democratic system.
"All the Arab countries' constitutions are based upon the principle that their countries' religion is Islam and that it's the source for legislating," he said.
"Iraq subscribes to this vision and the view that Islam is the official religion and that it's the source of legislation, although there are some issues in life where we can refer to other sources."
Hammoudi said those drafting the constitution would reach out to a wide range of Sunni Arabs.
Sunnis prevailed under the secularist Saddam Hussein regime, although an estimated 60 percent of the people were Shiite Arabs.
The toppling of Saddam and de-Baathification alienated Sunnis from the new political process and brought Shiites and Kurds newfound power.
The Sunni insurgency that emerged has targeted Shiite and Kurdish targets as well as coalition soldiers.
Many Sunni leaders now realize they should have participated the January 30 elections that chose the transitional assembly.
Other developmentsA top insurgent figure, called Emir Abu Ghraib, was captured Thursday during a crackdown in Baghdad called Operation Lightning, a Defense Ministry official said. Ghraib, which is not his real name, is believed to be responsible for the killings of 100 Iraqi civilians, 40 Iraqi security forces and the attack on the Abu Ghraib prison complex in early April, the official said. Operation Lightning consists of widespread cordons, roadblocks and house-to-house searches.An attorney for Saddam urged the country's new government to bring formal charges against the ousted Iraqi leader if it expects to put him on trial this summer. The remarks Wednesday by attorney Giovanni Di Stefano came one day after the president of Iraq's transitional government, Jalal Talabani, said he hopes to see Saddam tried within two months. (Full story)The United States, the European Union and Iraq announced an international conference on Iraq. It will be held in Brussels, Belgium, on June 22.
CNN's Ryan Chilcote, Enes Dulami, Mohammed Tawfeeq and Kianne Sadeq contributed to this report.