Earlier, Daesh fighters captured the 43 Iraqis from the Albu Obeid Sunni tribe in the battlefield town of Al Baghdadi, some 200 km northwest of the Iraqi capital Baghdad, Xinhua news agency reported citing the source.
Those abducted were believed to be local police and government-backed Sahwa paramilitary group members, and were later transferred to the nearby militants-held town of Heet, the source added, adding that the terrorists put the victims in iron cages and set fire to them.
The executions came after the killing of some 70 others during the past 10 days when Daesh militants carried out major attacks in Al Baghdadi and the nearby air base of Ain Al Asad which houses hundreds of US Marines.
However, their attacks on the air base were repelled by security forces and US aircraft, while fighting continued in the town after Iraqi troops regained control of large parts of it.
Meanwhile, the militants laid siege to a neighbourhood in Al Baghdadi town housing dozens of families of security members and Sahwa fighters, said the source, who confirmed that the residents were facing acute shortage of food and drinking water, as well as weapons and ammunition.
Why are families still in this town? It has been surrounded for months by IS. Did people actually think this would end well?
Ain Al Asad military base is used by Iraqi military forces, as well as roughly 300 US Marines deployed there as military trainers and advisers.
Daesh has seized around 80 percent of Iraq’s largest province of Anbar and has tried to advance towards Baghdad, but several counter-attacks by security forces and Shia militias pushed them back from western areas of the capital.
Since December last year, there have been insurgent attacks in the Sunni Arab heartland west of Baghdad which stretches through the Anbar province.