At least four policemen were killed by a roadside bomb in a village near the town of Falluja, west of Baghdad.
A car bomb killed at least two people at a bus terminal in a Shia district in the south of the capital.
The attacks come less than a week before US soldiers pull out of Iraqi cities, and a day after a bomb blast killed nearly 70 people in Baghdad.
More than 130 people were injured in the blast in a market place in Sadr City, a predominantly Shia area of the Iraqi capital.
Under an agreement with the Iraqi authorities, most of the 133,000 US troops in Iraq are due to leave the country’s cities and towns and withdraw to military bases by 30 June.
Combat operations across Iraq are due to end by September 2010 and all US troops will be out of the country by the end of 2011.
Surge in violence
In the Falluja attack, the policemen were killed when an improvised explosive device destroyed their patrol vehicle, officials said.
Falluja, in Anbar province, was once a major bastion of the insurgency, but the security situation has improved there in recent years.
The Baghdad car bomb, which killed two people, exploded in a bus station in the Baya district. About 30 more people were injured.
Nine US soldiers were also injured on Thursday when two roadside bombs hit their patrol in eastern Baghdad, the US military said.
Despite a recent surge in violence, the US military has said American troops would leave Iraqi cities as planned next Tuesday.
