Another man named as Mohammed Abdullah, who they claim is the mukhtar of the village of Big Bahiza in Diyala, is also beheaded.
At least seven captives are executed in the graphic film, in which the militants pledge continued allegiance to ISIS leader Abu Bakr al-Baghdadi.
It is unclear when and where precisely the footage was captured.
ISIS remnants continue to operate in several mountainous and desert regions of Iraq despite their territorial defeat in 2017.
The Hamrin Mountains, 160 kilometers north of Baghdad, straddle the northern provinces of Saladin, Diyala and Kirkuk. They have become a hotbed for the new insurgency developing in Iraq.
On Sunday, Iraqi counterterrorism forces killed the ISIS group’s “military governor” in the northern Hamrin Mountains and three of his aides in an operation backed by intelligence services and the US-led coalition, officials said.
“Based on info from the Iraqi National Intelligence Service, the Counter Terrorism Service targeted and eliminates the so-called Hamrin Mountains military governor of Daesh (ISIS) and his three aides,” read a tweet
by Yahya Rasul, spokesperson for the Iraqi Security Media Cell, late Sunday.
“The operation was supported by the Iraqi Army Aviation and aircraft from our Coalition partners.”
Two brigades of the elite Iraqi Counter-Terrorism Forces (ICTS) launched an operation last week
against ISIS remnants operating along the mountain range in the north of the country following a green light from Prime Minister Adil Abdul-Mahdi.
The headquarters of ISIS propaganda newspaper al-Nabaa was targeted on the first day of the offensive.
ISIS militants are exploiting security gaps opened up between Kurdish Peshmerga lines and areas controlled by the Iraqi Security Forces (ISF).
In the wake of the Kurdistan Region’s independence referendum, the Iraqi government launched an offensive against the Peshmerga, forcing it to withdraw from the territories considered disputed between Iraq and the Kurdistan Region.
The no man’s land between the rival armies has left ungoverned spaces where insurgents have been allowed to regroup.