Iraqi Industry Minister Osama al-Najafi escaped a bomb attack on his convoy north of Baghdad, but three of his bodyguards were killed, officials said.
A ministry spokesman said a roadside bomb exploded near the first car in Mr Najafi's convoy as it passed the town of Balad at 1230 (0930 GMT).
The Sunni Arab minister had been travelling home to Mosul in the north.
Senior Iraqi government figures have frequently been the targets of attacks by insurgents.
Mr Najafi had been attacked on six previous occasions, his spokesman said.
The minister was unharmed by the attack.
Before becoming minister of industry and minerals, Mr Najafi led several electrical engineering teams reconstructing a number of power stations throughout Iraq.
The attack came as US-led forces handed over responsibility for security in two of Iraq's provinces to the Iraqi armed forces.
Responsibility for the southern provinces of Qadisiya and Wasit was transferred at a ceremony in Diwaniya overseen by the commander of multi-national forces in Iraq, US Gen George Casey.
They had previously been under Polish command in Multi-National Division Centre-South.