This has been one of the most violent weeks in Iraq in recent months.

A bombing in Baghdad killed three U.S. soldiers and wounded nine others.

Another bomb went off inside a police station killing three Iraqi officers.

And a suicide bomber killed a group of Sunnis waiting in line to get their paychecks.     

This week's bombings are adding pressure on the Iraqi government that's trying to prove it can handle security challenges when U.S. troops leave later this summer.

President Obama has ordered combat troops to be out of Iraq by the end of June.