Iraqi officials say a Baghdad car bomb has killed four people and wounded 15 more. In northern Iraq, a bomb in a cart full of toys has killed one child and wounded another 13. And the U.S. military is investigating an air raid that killed 15 civilians on Thursday.  VOA's Jim Randle reports from northern Iraq.

The military says the air raid targeted senior al-Qaida leaders in the Lake Thar Thar region, northwest of the capital, and that ground and air assault troops acted on intelligence reports of insurgent activity in the area.

A U.S. military spokesman expressed regret at the civilian deaths, but said militants had placed Iraqi women and children in danger by their presence and actions.

Iraq's continuing violence is the subject of a new report from the United Nations that says bloodshed and a deepening humanitarian crisis continue to drive thousands of Iraqis from their homes.

Ali Hussein, an ethnic Kurd, says his family fled Mosul to a camp for displaced persons in northern Iraq after terrorists tried to kill him, kidnapped and killed his brother, and then targeted him again in the marketplace.

Hussein and his wife, children and his dead brother's daughter now have a makeshift home in an abandoned building in an army camp outside Mosul.

Hussein is one of about 2.2 million displaced people inside Iraq along with a similar number of refugees who have fled the country.

The U.N. report says civilians like Hussein are suffering devastating consequences of the ongoing violence.

Thursday's report by the U.N. Assistance Mission for Iraq also called for investigations into the actions of foreign security contractors, and alleged mistreatment of detainees held across Iraq.

Meanwhile, Turkish troops remain poised for a possible military operation against Kurdish rebels in northern Iraq.

Turkey's Prime Minister Recep Tayyip Erdogan.

Mr. Erdogan says his country will deal with any international criticism that follows military action against guerrillas of the Kurdistan Workers Party (PKK), who have been staging attacks from bases in northern Iraq against Turkish security forces in southeastern Turkey.  The PKK seeks autonomy for Turkey's Kurds. 

Turkey's government will seek parliamentary approval next week for possible cross border military action against the PKK in northern Iraq.

Officials in the autonomous Kurdistan Region of Northern Iraq say they understand Turkey's concerns about PKK violence, but the head of the regional government's Department of Foreign Relations, Falah Mustafa Bakir, says a violent response is not the solution.

"PKK is a problem," he said.  "It has to be handled. There has to be a political approach in order to solve that problem. Military means cannot provide the solution."

The United States is also urging Turkey not to take military action, because it could destabilize Iraq's mostly peaceful northern region.