But analysts say the media and many politicians are focusing too much on relations between Iraq's Shi'a and Sunni Muslim communities.
Mustafa Alani is an associate fellow in the Middle Eastern program at the Royal United Services Institute for Defense Studies in London. He says there are no serious precedents in Iraqi history to support theories of sectarian violence.
"I think this is exaggerated. Actually, Iraq was established in 1921 as a secular state. It is different from other countries like Saudi Arabia or later [after the Islamic Revolution] Iran. In Iraq, basically, the constitution, the law, established a secular state. Sectarian division was not really a major issue in Iraqi politics. I think there is a great exaggeration emphasizing [sectarian] divisions within Iraqi society," Alani said.
It is widely believed that Sunnis have always been the ruling elite in Iraq and that the Shi'a have long been suppressed. However, Iraqi Shi'as remained loyal to their country when Iraq fought a bitter war with predominantly Shi'a Iran from 1980 to 1988.
Alani says that even during the Sunni-dominated former regime of Saddam Hussein, which was responsible for the deaths of thousands of Shi'a after the Gulf War in 1991, Shi'a and Kurds were represented in the upper echelons of power. While it's true that Hussein mostly trusted Sunni Arabs from his own clan, loyalty to Hussein and his Ba'ath Party mattered most.
Alani says the U.S.-led invasion of Iraq last year and the hardships of occupation have created a situation in which people are inclined to stick close to their religious communities. He says this gives an impression of sectarianism. But he says this trend is observed in all societies in times of war or conflict.
"Yes, you might find now at the time of [conflict] huge change in the Iraqi political structure, you might find people who basically are trying to stick to their [religious] community as a means of protection. But I don't think, in reality, the divisions in Iraqi society are [so] deep or genuine that they might basically undermine the stability of the state," Alani said.
Ammar al-Shabandar is the director of the Iraq Foundation, a U.S.-Iraqi group promoting human rights and democracy. He also says there are no grounds to fear sectarian strife in Iraq and does not believe that last week's bombings are a precursor to that.
"That assumption [on a sectarian war] is absolute nonsense. I mean, people here -- both Sunnis and Shi'a -- are very well aware that none of them will be able to win such a war if it breaks out. So, everybody is keen on calming down. They're basically addressing their constituencies. I mean, both sides are calming down their people. And I think since the bombings of Karbala and Kadamiya [in Baghdad], the situation has been very calm," al-Shabandar said.
Many influential Iraqi political parties have been formed along sectarian lines, however. The most important are the Supreme Council for the Islamic Revolution in Iraq (SCIRI), the Islamic Dawa party, the Iraqi Islamic Party, and the Kurdish Islamic Union. All are represented on the Iraqi Governing Council.
"During the conference, the Iraqi exiles were not able to agree on how the leadership council had to be elected," says al-Shabandar, "and it was decided that main religious and ethnic parties had to simply send their representatives to the body. Last year, according to this model, the Iraqi Governing Council was formed."
"It really didn't exist before that,” al-Shabandar says. “Nobody thought along those lines of dividing power and influence. And what's happened, in Baghdad [after the war], they just followed the solution they knew would work -- I mean the solution they had already experienced and [which] they knew worked. So, they followed the sectarian divisions along sectarian and ethnic lines."
Al-Shabandar says the U.S. civilian administration in Iraq had to accept the divisions, which had already been formalized.
"[Iraq's top civilian administrator L. Paul] Bremer dealt with the issue as with a de facto issue. He is here. He needs to find a solution [for] setting up the [Iraqi] Governing Council. There was no way out," al-Shabandar said.
But al-Shabandar says he fears sectarianism could become a factor in the future. He says sectarianism will be encouraged if top Shi'a cleric Grand Ayatollah Ali al-Sistani manages to achieve a more prominent role for Islam in the permanent Iraqi constitution.