A roadside bomb hit Iraqi Finance Minister Rafaie al-Esawi's convoy west of Baghdad as he left a meeting on Sunday, wounding two of his guards, his office and security sources said.
It was not clear whether Esawi was the target of the bombing. The Sunni Muslim minister is caught up in a crisis that has triggered protests in Sunni regions and is straining Shi'ite Prime Minister Nuri al-Maliki's power-sharing government.
"A roadside bomb exploded near his convoy. His car was not hit and he is safe, but two guards were wounded," a spokesman for Esawi's office said.
Police sources confirmed the convoy had been hit by shrapnel, but said there had been no injuries.
Thousands of Sunni Muslims have taken to the streets over the last three weeks to demonstrate against Maliki's government.
The protests are stirring worries that Iraq could slide back into the sectarian confrontation of its recent past.
They erupted in late December after officials arrested members of Esawi's security team on terrorism charges. Authorities denied that the case was political, but Sunni leaders rejected the arrests as part of a crackdown on their community.
Sectarian tensions are still raw in Iraq after the intercommunal slaughter that killed tens of thousands a few years after the 2003 invasion that ousted Sunni strongman Saddam Hussein.
Violence has eased sharply but, a year after the last U.S. troops left, Iraq's government is mired in infighting over how to share power among the Shi'ite majority, Sunnis and ethnic Kurds.