Jihadis fighting for the Islamic State in Iraq have brutally murdered one of their own senior leaders amid rumours that he was planning to stage a coup.

Abu Usman al-Hassan - the top ISIS commander in its Mosul stronghold and a member of the terror group's advisory board - is believed to have been killed some time last week.

According to local reports, al-Hassan was sentenced to death following a short trial, at which he was formally accused of conspiracy. Having been found guilty of the crime, the jihadi was executed by an unknown method at an ISIS military base to the west of the city.

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Terrorists: Abu Usman al-Hassan is understood to have been the top ISIS commander in its Mosul stronghold. The depraved jihadis (pictured) seized control of the city last June following a lightning advance

The execution of al-Hassan is understood to have caused major divisions within the Mosul branch of the terror group with a number of jihadis said to have abandoned their posts.

Scores of Syrian and Arab fighters - who make up the majority of ISIS' fighting force in and around Mosul - have already withdrawn in protest at the killing, according to Business Insider.

Those who have fled the city in frustration with Mosul's new commanders are understood to have made their way to ISIS' de facto capital in the Syrian city of Raqqa.

It is likely that once they arrive, they will either raise formal complaints against the execution of al-Hassan with the extremists' leadership, or will apply to live and fight under the command of a different jihadi jurisdiction.

One witness, speaking to Iraq Press, was quoted as saying that the trial came after ongoing disagreements between al-Hassan and his deputies.

Others said it came as foreign jihadis gained influence in the area, effectively splitting Mosul into Arab and non-Arab camps. With the former likely to have been led by al-Hassan, that would explain why so many Arab jihadis have subsequently fled Mosul for Raqqa.

'He was accused of conspiring against the 'caliphate state,' the local said without elaborating.

Friends: Abu Usman al-Hassan - the top ISIS commander in Mosul and a member of the terror group's advisory board - is said to have been a close friend of overall leader Abu Bakr al-Baghdadi (pictured)

ISIS JIHADIS BEHEAD TWO WOMEN FOR 'WITCHCRAFT' IN SYRIA ISIS jihadis have brutally beheaded two women in Syria for alleged 'sorcery.' It is believed to be the first time ISIS have executed a woman in Syria for crimes of 'witchcraft' and 'sorcery', the Syrian Observatory for Human Rights monitor said. 'The Islamic State group executed two women by beheading them in Deir Ezzor province, and this is the first time the Observatory has documented women being killed by the group in this manner,' Observatory chief Rami Abdel Rahman said. The Britain-based monitor said the executions took place on Sunday and Monday and involved two married couples. In both cases, the women were executed with their husbands, with each pair accused of witchcraft and sorcery. According to the monitor, IS has executed more than 3,000 people in Syria in the year since it declared its Islamic "caliphate" in Syria and Iraq. Nearly 1,800 of them were civilians, including 74 children. Advertisement

According to a number of sources on the ground in Syria and Iraq, al-Hassan was a close friend of the terror group's leader overall leader - the self-declared caliph, Abu Bakr al-Baghdadi.

It is not known how aware al-Baghdadi was about the trial and execution in advance, nor whether he supported the action.

According to many reports the terror leader was left severely disabled or even paralysed by an American air strike in western Iraq earlier this year, and that the day to day running of ISIS has passed over to one of his right hand men.

The news comes as the United States and its allies staged 18 air strikes on ISIS targets in Syria and Iraq earlier this week in the latest round of daily attacks on the militant Islamic group.

Seven of the strikes focused on an area near Al Hasaka, Syria, hitting tactical units, vehicles and a tank, while targets near Ar Raqqa and Dayr Az Zawr also were hit,

The strikes took place on Monday, the Combined Joint Task Force said in a statement revealed in a statement yesterday.