BAGHDAD, Iraq (CBS) -- Six people were killed and two others were wounded after two mortar shells struck a residential area in the north-west Baghdad suburb of Chikok on Tuesday (October 23), police sources said.

However, witnesses said the blast was caused by three parked car bombs in two residential areas in Chikok.

The blast damaged surrounding houses and shattered glass in the windows.

"I was about to wake my children up to go to school when the blast took place collapsing walls and shattering the glass in the windows. Thank God the curtains prevented flying pieces of glass from injuring my daughters. Thanks God none one of them were hurt. When will we stop being killed like this? Let the people responsible give us a time frame so we can sit in our houses and not venture outside. The problem is that every year there is death and killing and terrorism," said Lamia Sami, a resident of the area.

In a separate incident, two mortar shells struck Baghdad's northern Shi'ite district of Shula, killing one civilian and wounding 10 others, according to police sources.

Hospital sources put the death toll of the blasts in Shula and Chikok to eight people killed, with 24 others wounded.

Violence in Iraq has eased since its height in 2006-2007 when sectarian fighting killed thousands of people. But Sunni Islamists and an al Qaeda affiliate still launch regular attacks, seeking to undermine the Shi'ite-led government.

September was the bloodiest month in two years. Militants killed 365 people, most of them in bomb attacks and shootings according to government figures released this month.

Iraq has been racked by sectarian slaughter since the overthrow of Saddam Hussein. Although it is now far off its peak of 2006-2007, the violence has been increasing since the last U.S. troops left in December 2011 as political tensions among Iraq's main Shi'ite, Sunni and Kurdish factions have increased.