Iraqi officials say a truck bomb has killed at least 20 people and wounded 27 others in a Kurdish village in northern Iraq.
Authorities say the blast tore through Wardak village before dawn, killing people as they slept in their homes. Several houses collapsed, trapping and injuring other victims.
Police say they prevented a second suicide bomber attack, shooting and killing an assailant before he could strike.
The Kurdish village lies east of Mosul, the capital of Nineveh province. It is one of the last regions where insurgents still have a firm position, after being forced out of other areas by Iraqi and U.S. troops.
Tensions between ethnic Kurds and Arabs are on full display in such towns as Wardak. Iraq's semi-autonomous Kurdistan Regional Government would like to extend its control in the oil-rich region, while Baghdad wants to keep it under the central government.
International Crisis Group political analyst Peter Harling says there is a wide range of possible motives for the attacks, but unresolved issues between Arabs and Kurds are an underlying cause of problems.
"The exact distribution of lands, of resources, and of power along these lines is an issue which has been left completely unattended since 2003," he said. "And I think the Iraqi government, Iraq as a whole and the U.S. are now paying the price for that."
The Damascus-based political analyst, says the constitutional and territorial issues involved require more compromise than either the central government or Kurdish side has yet to show.
"A solution is to bring in outside leverage, but that would mean the U.S. working hand-in-hand with other players that have leverage in Iraq, and I do not see that happening anytime soon," he added. "Anyway, not before some progress is made, for example, with Syria and America, and more importantly in the American-Iranian relationship.
The issues are likely to play an important part in national elections set for early next year.