Gunmen kidnapped six men from different homes in a town south of Baghdad and later shot them dead, according to officials in Iraq.
A police officer said the gunmen broke into the homes at dawn on Sunday in the town of Latifiyah, a mainly Sunni town 20 miles south of Baghdad. No one immediately claimed responsibility for the killings.
A medical official confirmed the casualty figures.
Last year, Iraq saw its highest death toll since the worst of the country's sectarian blood-letting began to subside in 2007, according to United Nations figures.
The country will hold its first parliamentary elections since the withdrawal of US troops on April 30.