Nearly two years after the U.S. troop withdrawal, Iraq is in the midst of a deepening security crisis as an al-Qaida affiliate wages a relentless campaign of attacks, sending the death toll soaring to its highest level since 2008.

In the latest violence, nine car bombs tore through markets and police checkpoints in Baghdad on Sunday, killing scores of people.

The bloody campaign has virtually erased the security gains made in the past five years. More than 5,300 Iraqis have been killed this year.