Shocking new images released by the Islamic State (Isis) show its fighters smashing the heads of two men who were accused of murdering three women in Mosul.

The Isis fighters said the men were "criminals" who had killed three women to steal money from them. The images released on Thursday showed Isis fighters, clad in black and wearing face masks, smashing boulders on the heads of the tied up men lying face down on the ground.

The Isis police said since the "criminals" had killed their victims with stones, it was justified they were killed by stones too.

The Isis photo report showed a crowd of local civilians, including children, looking on at the scene with horror.

Prior to the execution, an Isis fighter announced the crimes of the two men who were blindfolded, with their hands tied behind their back. They were made to lie face down on the ground.

The report concluded that the "punishment" given to the two would set an example to the people of Mosul.

After taking over large swathes of land in Syria and Iraq, the Islamic State introduced its version of Sharia law in areas under its control. Execution by beheading, stoning and crucifixion have become common occurrence.

Mosul, which is the second largest city in Iraq, has been under Isis control since June and is the group's de facto capital in Iraq.