The British Broadcasting Company reports that the coalition forces, led by the United States, blame the attack on supporters of former dictator Saddam Hussein, who repeatedly oppressed the majority Shi'a population during his reign. They also cite terrorist group, al-Qaeda, as a possible perpetrator of the attack.
Many feel this latest round of violence, the deadliest in Iraq to date, could lead to internal conflict between the different religious and ethnic groups within the country.
Friday's attack could stir up existing tensions between the Shi'a Muslims, predominantly located in the south of the country, and the minority Sunni Muslim population.
Jordan newspaper, Al Arab al-Yawm, called the attack against Ayatollah Hakim a "crime against humanity," that would inevitably lead to more internal conflict.
"Peace and stability in Iraq is now hindered," read the Jordanian paper.
Lebanon newspaper, Al-Safir, writes, "Iraq has entered a new cycle of massacres which is going to lead the country into darkness."
The Al-Watan newspaper based in Qatar writes that Iraq will "remain in chaos and bloodshed," due to the Najaf bombing.
"Shi'a unity was the starting and end point of national unity. Iraq will become the battle ground in a sectarian war."
Not only is there a split in Islam, but divisions also exist within the Shi'a tradition. The sect further divides itself into religious and secular factions and leaders fit into either the activist or the quietist categories.
The Shi'a population needs a leader, writes Roger Hardy, a Middle East Analyst for the BBC.
"Whoever carried out last week's car-bomb attack, the motive may have been to sow fear and division among the Shi'a, and provoke tension between the country's Shi'a majority and Sunni minority. The need for leadership could hardly be greater," Hardy writes on the BBC's Web site.
Some say the U.S. led coalition has failed to provide adequate security in post-war Iraq.
"The former Iraqi regime of Saddam Hussein was credited with maintaining social, political, ethnic and religious harmony by an iron fist, now with the absence of central and effective control over the country, the stage is set for more partisan conflict," read an editorial in Sunday's Jordan Times.
Ahmad Chalabi, a member of the Iraqi Governing Council, wrote in Sunday's Washington Post, "An extended occupation under the coalition leading to popular resistance provides the political power to Saddam's plan and plays into his hands. The politics of occupation is well practiced in the Middle East - the coalition would be wise to avoid it."
Another member of the IGC, Shi'a leader Muhammad Bahr al-Ulloum, said, on the BBC's Web site, that he doesn't favor the U.S. policy on security. He suspended his participation in the IGC, saying he plans to establish armed militias to handle the security issues in the cities of Najaf and Karbala.
According to BBC correspondent, Magdi Abdelhadi, located in Najaf, these statements by a respected Shi'a leader signal "restless among Iraqis at the American inability to improve security.
With the situation in Iraq becoming increasingly more dangerous and the diminishing lack of trust in the U.S. led coalition, President Bush decided yesterday to go to the U.N. to discuss expanding U.S. military presence into a multinational force, according to Tuesday's New York Times.

- Compiled by Sarah Stiles