The militants took some 50 men from Tal Ali village, around 240 kilometers (170 miles) north of Baghdad, according to residents. The men were loaded onto trucks and driven away, they said, speaking on condition of anonymity out of fear of retribution.
The militants had retreated from the village the day before, fearing an attack by the Iraqi army. When they left, residents set fire to an Islamic State flag.
In Baghdad, police officials said a suicide bomber rammed his explosives-laden vehicle into a police checkpoint in the Shiite neighborhood of Kazimiyah, killing 14 people, including five policemen. About 26 people were wounded and several cars were burnt in the attack.
A medical official in a nearby hospital confirmed the casualty figures. All officials spoke on condition of anonymity because they were not authorized to speak to the media.