Suicide bombings and ambushes by insurgents killed at least 21 people in Iraq Sunday as Iraqi security forces began a big security sweep in Baghdad.
The operation is aimed at stopping insurgents who have killed more than 600 people in the last month.
Iraqi soldiers and police began setting up checkpoints on the southern and northern outskirts of the city early Sunday and later began street-to-street sweeps.
A suicide car bomber killed nine Iraqi soldiers at one of the checkpoints about 20 kilometers south of Baghdad. Other attacks killed at least 12 Iraqi police or civilians in and around the capital.
Some information for this report provided by AP and Reuters.