A roadside bomb killed the governor of southern Muthanna Province yesterday, police said, the second assassination of a top provincial official in just over a week.
A bomb on a motorcycle also exploded in a busy market district in central Baghdad, killing at least three people and wounding 11, a police official said in the capital.
The violence came as Prime Minister Nouri al-Maliki arrived in Syria for his first visit to Damascus since he took office in May last year.
The blast struck the SUV carrying Governor Mohammed Ali al-Hassani at approximately 9am, shortly after his convoy departed from his home in Rumaitha en route to his office in the provincial capital of Samawah, about 370km southeast of Baghdad.
Al-Hassani, his driver and a guard were killed, while his office manager and two other guards were seriously wounded, police said.
A curfew was immediately imposed on Samawah and new checkpoints were erected.
On Aug. 11, the governor and police chief of another southern province, Qadasiyah, were also killed in a roadside bombing attack. Governor Khalil Jalil Hamza and police chief Major General Khalid Hassan were killed as they returned to the provincial capital of Diwaniyah from a funeral for a tribal sheik.
Both governors were members of the influential Supreme Islamic Iraqi Council (SIIC), a group led by Shiite politician Abdul-Aziz al-Hakim whose loyalists have been fighting the Mehdi Army militia for control of the oil-rich south as British-led forces gradually withdraw from the area.
Al-Hassani, 52, is from a prominent clan in the area and had been governor for about two years despite several attempts by rivals in the provincial council to sack him.
Police quickly laid the blame on the Mehdi Army, which is nominally loyal to radical Shiite cleric Moqtada al-Sadr and has been involved in several recent clashes with its rivals.
"There was nothing against the governor inside the province except the confrontations between the Mehdi Army and the SIIC, which have claimed the lives of dozens of people," an officer said, speaking on condition of anonymity because he feared retribution.
Meanwhile, Sadr said yesterday he would welcome a planned expansion of the UN mission in Iraq if it was designed to help Iraqis rebuild their country.
In an interview in Britain's daily Independent newspaper, Sadr stressed the UN must not become "just another face of the American occupation" in Iraq.
"I would support the UN here in Iraq if it comes and replaces the American and British occupiers," he said. "If the UN comes here to truly help the Iraqi people, they will receive our help in their work."
The UN Security Council decided earlier this month to widen the UN's mandate in Iraq, implying an increase in staff for the first time since the world body effectively withdrew from the country after a bomb blast at its Baghdad headquarters killed 22 people four years ago.
The Security Council resolution calls on the UN to take on the challenge of promoting national reconciliation and dialogue between Iraq and its neighbors.
Sadr also said in the interview that British troops had been defeated in Iraq and forced by resistance fighters into a retreat from the south of the country.
Mehdi Army fighters played an "important role" in driving the British out, he said.
"The British have given up and know they will be leaving Iraq soon," he said in the interview. "They are retreating because of the resistance they have faced. Without that they would have stayed for much longer, there is no doubt."