By
The four family member parents and two daughters in their 20s were all shot in the head overnight by gunmen who spared a third, seven-year-old daughter, interior ministry and security officials said.
"This was probably a terrorist crime, which we are investigating," said Baghdad security spokesman Major General Qassim Atta.
Violence has sharply fallen in Iraq since its peak during sectarian killings of 2006 and 2007, but bombings, shootings and kidnappings remain common.
The UN envoy to Iraq, Ad Melkert, said this month that violent incidents still occur on average 25 times per day ,although the number was "a lot lower than what it used to be."