The latest killings brought the number of ISIS victims in the Middle East to over 3,000 since the terrorist declared a state or caliphate of their own in June last year.

"Many of the charges against those executed are recorded as blasphemy and spying, but others include sorcery, sodomy, practicing as a Shia Muslim," the human rights group said.

The children and women met unholy deaths in the hands of ISIS as they were accused of practising "magic" and for refusing to fast, Fox News reported.

This week, two children were crucified in the Mayadin, Deir Ezzor province in eastern Syria after ISIS leaders accused them of "improper fasting" during the Islamic month of Ramadan, which runs from June 17 to July 17.

Other children, said the Syrian Observatory, died fighting for their lives.

"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," said Rami Abdel Rahman, of the Syrian Observatory for Human Rights.

"The practising of anything that is not approved by the ISIS under their very strict interpretation is 'haram' or forbidden," said Veryan Khan, editorial director for the Florida-based Terrorism, Research & Analysis Consortium.

"If the Islamic State thinks that sorcery is real, then black magic would be a threat to them and seen as a danger."