Speaking at a news conference on Thursday amid reports of fresh attacks, Ayad Allawi said he was forming a General Security Directorate, a domestic intelligence agency which he hoped would infiltrate and expose those behind the attacks.
Hours earlier a suspected car bomb killed up to 10 Iraqis including three policemen in an Iraqi town west of Baghdad.
The blast took place near the main police building in Haditha, 200km west of Baghdad.
Hospital officials said three policemen and seven civilians were killed, while 40 people, seven of them from the police force, were injured in Haitha, a town west of Baghdad.
Abd al-Adhim Muhammad, Aljazeera's correspondent in Baghdad reported that the explosion took place at 09:00 (05:00 GMT) when a car strapped with explosives slammed into the entrance of the police station, killing three policemen and wounded another nine.
Interim PM Ayad Allawi wants to
create an intelligence agency
In the southern city of Karbala, police Colonel Karim al-Hasnawi said a car bomb exploded around midnight about 500m from a base where Bulgarian troops are garrisoned after police had chased and surrounded the vehicle.
He said two bombers were killed but there were no other injuries.
Bulgaria has a 450-strong light infantry battalion based on the outskirts of Karbala, about 110km southwest of Baghdad.
Another explosion on Thursday caused damage to oil pipelines linking the Kirkuk refinery with the Biji refinery, north of Baghdad. While another pipeline southwest of Basra in the Askari area was also attacked.
On Wednesday, a suspected car bomber killed 11 people and wounded 30 in Baghdad in the first big attack in the Iraqi capital since an interim Iraqi government took over from US-led occupiers on 28 June.