The worst attack has been a suicide bombing on a Baghdad bus that claimed at least a dozen lives. There was another suicide attack at a restaurant in Mosul.
Two Macedonian contractors were freed by kidnappers four days after they were abducted in Basra, a British official said without giving further details.
Back in Baghdad, a bomb left in a bag near a stand selling tea and sandwiches killed some day laborers waiting for jobs.
A vendor says a man who bought tea from him and drank it left the bag and walked away before it exploded. The distraught vendor says "We need a solution. We can't live like this."
Meanwhile, the U.S. ambassador to Iraq warned Iraqi politicians they risk a loss of American support if they do not establish a genuine national unity government, saying the United States will not invest its resources in institutions run by sectarians.
U.S. Ambassador Zalmay Khalilzad delivered his blunt warning during a rare press conference after signs that talks on a new government following the December elections were not going well because of sharp differences among the country's Shiite, Sunni Arab and Kurdish political parties.
Failure to establish a unity government that includes a strong role for Sunni Arabs would fail to undermine the Sunni-dominated insurgency and throw into question U.S. plans for a phased withdrawal of the 138,000 American troops.
Khalilzad said that overcoming the sectarian and ethnic divide requires a government of national unity, which is "the difference between what exists now and the next government." The outgoing government is dominated by Shiites and Kurds.
Khalilzad told the Shiites that the key security Defense and Interior ministries must be in the hands of people "who are nonsectarian, broadly acceptable and who are not tied to militias."
The ambassador reminded the Iraqis that the United States has spent billions to build up Iraq's police and army and "we are not going to invest the resources of the American people and build forces that are run by people who are sectarian."
In other developments: