BAGHDAD — Iraq's prime minister warned Saturday that efforts to create an autonomous Sunni region within Iraq would divide the country and lead to "rivers of blood."

His comments came as a government crisis has strained ties between two main Muslim sects, Sunnis and Shiites, to the breaking point.

Nouri al-Maliki, the Shiite prime minister, is engaged in a showdown with the top Sunni political leader in the country. His government has issued an arrest warrant for Sunni Vice President Tariq al-Hashemi for what al-Hashemi says are trumped-up charges that he ran hit squads against government officials.

Since al-Maliki formed his government last December, minority Sunnis have been complaining of being marginalized by the Shiite-led government, prompting some Sunni provinces to call for turning into an autonomous region similar to the northern Kurdish region.

As an autonomous region, they would be able to conduct their own security affairs and have more independence in attracting investment. While the regions would still be part of Iraq, it would weaken Baghdad's control. Many worry that it would be the first step to breaking up the country along sectarian lines.

The calls have been repeatedly rejected by al-Maliki.

On Saturday, al-Maliki renewed his rejection to forming regions on a "sectarian basis," saying it would lead to "dividing Iraq and to rivers of blood."

"I can't reject this issue (forming regions) since it is allowed by the constitution," he told representatives from Sunni Salahuddin province, one of three Sunni-dominated provinces which has seen calls for more autonomy. Diyala and Anbar provinces have also seen cries for more autonomy.

"But doing it now means dividing Iraq on a sectarian basis while our country is unified," he said.

Tensions between minority Sunnis and Shiites have skyrocketed in recent days, laying bare an underlying mistrust that has never really gone away, despite years of effort to overcome it. Minority Sunnis fear the Shiite majority is squeezing them out of any political say, and Shiites suspect Sunnis of links to insurgency and terrorism.

Iraq's anti-American Shiite cleric, Muqtada al-Sadr, launched an initiative Saturday calling for peaceful coexistence among all Iraqis after the withdrawal of U.S. troops from the country. The last soldiers left Dec. 18.

Al-Sadr, whose militiamen were blamed for sectarian killings during the worst years of Iraq's violence, is seeking to assert his political weight Iraq after the U.S. pullout.

Al-Sadr's proposal comes just two days after a terrifying wave of Baghdad bombings killed 69 people and wounded nearly 200. The bombs tore through mostly Shiite neighborhoods of the Iraqi capital, evoking fears the country could descend into a new round of sectarian violence.

Al-Sadr's associates handed out to the media a 14-point "peace code" proposal written by the radical cleric. It warns against spilling Iraqi blood and urges respect for all religions, sects and ethnic groups.

Al-Sadr's aide Salah al-Obeidi described the code as an attempt "to preserve the unity of the country and save it from fighting."

It remained too early to say how much traction al-Sadr's proposal could gain among Iraqis or the country' top leadership.

Also Saturday, two policemen were killed and two other people were wounded when a roadside bomb exploded in Hawija, 150 miles (240 kilometers) north of Baghdad, said Kirkuk police commander Brig. Gen. Sarhad Qadir.

Associated Press writer Qassim Abdul-Zahra contributed to this report.