The new service, the General Security Directorate, "will annihilate those terrorists groups, God willing," Prime Minister Iyad Allawi said during a news conference.
Attackers detonated a car bomb near police and government buildings in the western city of Haditha, killing 10 Iraqis, including three police officers. Twenty-seven people were wounded.
Police apparently thwarted a second attack in Karbala, where police chased a car after receiving a tip it was filled with explosives. The two people inside detonated their bomb, killing only themselves and causing no other casualties.
The violence came a day after a suicide attacker in Baghdad killed at least 10 people in a car bombing near Iraqi government headquarters and insurgents assassinated a provincial governor in an ambush of his convoy.
Police and government officials have repeatedly been targeted by insurgents, who view them as lackeys of U.S. forces here.
In other developments:
The violent insurgency that has wracked the country since the fall of Saddam's regime 15 months ago has continued since U.S. forces handed power over to Iraq's interim government.
Since taking power, Allawi's government has made clear it intended to crack down on militants who have caused chaos with assassinations, bombings, sabotage and other attacks. The violence has hampered efforts to rebuild and recover after war and years of international sanctions.
The government has passed emergency laws giving Allawi the power to declare curfews and impose limited martial law to curb the violence and has repeatedly threatened the militants.
The new security service appears to be another step in the fledgling government's efforts to tackle the violence.
In remarks published in the al-Hayat newspaper, Allawi was quoted as saying Iraq has arrested operatives linked to al Qaeda and is seeing increasing coordination between the terror network and Iraqi insurgents loyal to ousted dictator Saddam Hussein.
Allawi said that among al Qaeda operatives arrested by Iraqi forces were the driver of Abu Musab al-Zarqawi, a Jordanian linked to al Qaeda who is accused of deadly attacks and kidnappings in Iraq and elsewhere.
Allawi also said millions of dollars are being channeled by Saddam loyalists in neighboring countries to operatives to carry out terror attacks.
He specifically mentioned Jordan and Syria, but told the London-based pan-Arab newspaper that his criticism wasn't of governments but of those who abused the hospitality of countries that took them in when they fled Iraq.
Allawi told reporters that he had asked Bangladesh, India, Pakistan, Morocco and Egypt to contribute troops to the multinational force to help him secure the country. He also announced that he would be going on his first foreign tour as prime minister to nearby Arab countries.
"We would like to strengthen our relationship with our neighbors and we are making this a priority," he said.
Insurgents detonated a massive car bomb Wednesday at a checkpoint just outside the so-called Green Zone, former home to the U.S. occupation government and currently home to the Iraqi interim government and the U.S. and British embassies.
The blast ripped a deep crater in the road and killed 10 Iraqis, many as they waited in line to apply for jobs with the government, the Health Ministry said. The U.S. military said 11 were killed.
Hours later, insurgents tossed hand grenades and fired machine guns at a convoy transporting Nineveh Gov. Osama Youssef Kashmoula, killing him and two of his guards, Iraqi and U.S. military officials said. Mosul is the largest city in Nineveh province.
Kashmoula was attacked between the cities of Beiji and Tikrit north of Baghdad as he traveled to the capital, the U.S. military said. Four of the attackers were killed in the fight, Mosul officials said.