The Islamic State group has executed 13 civilians in the city of Hawija, in the Kirkuk province of Iraq. One of its own leaders also escaped the region with $300,000, which is believed to have been collected through the robbing of local residents.

The Islamic State group â€” also known as the Islamic State of Iraq and Syria (Isis) or the Islamic State of Iraq and the Levant (Isil) â€” had "beheaded 13 civilians in the Riyad area in Hawija, 55 km southwest of Kirkuk," Iraqi News quoted sources in the the Kirkuk province as saying.

"The execution was carried out after the Sharia court passed out a verdict, charging them of facilitating the escape of several families from Hawija to Salahuddin province and other areas in Kirkuk," the source added. Isis has been controlling Hawija since mid-2014, and it is one of their biggest strongholds in Kirkuk.

Many of the group's own members are trying to flee it or dissociate themselves from Isis. Any such move would further weaken the already weak hold Isis has in the region.

To keep that from happening, it is resorting to extreme measures, like killing people who attempt desertion. In one such instance, flamethrowers were used to kill six militants who had tried to desert Isis, in a very public execution that was meant to act as a deterrent for other members.

It doesn't seem to be working, because another report from Iraqi News said an Isis leader had fled with $300,000 collected by blackmailing and looting residents of Hawija.

The report quoted Al-Hashed al-Sha'abi official Jabbar Maamouri as saying in a statement: "Isis leader Abu Jihad Saudi fled Hawija, situated to the south-west of Kirkuk, to an unknown destination, taking around $300,000 with him. This money was collected by force or by blackmailing different families."

Maamouri added: "Several Isis leaders, in the recent past, have escaped Hawija by taking a lot of money looted from the families. The leaders took the escape route after they realised their [Isis'] days in the city had been numbered, especially after their overwhelming defeat in Anbar, Salahuddin and Diyala."