Inside Sinjar
A deflated football lies next to a building hit by an air strike John Moore/Getty Images

Brutal Isis militants executed a seven-year-old boy by firing squad after he was heard swearing while playing a game of football with his friends. The boy named locally as Muaz Hassan, was playing on Monday 2 May in Isis's de facto capital of Raqqa when a militant walked past and said he heard him of swearing.

After dragging the boy in front of an Isis Sharia court in the northern Syrian city he was convicted of "blasphemy" and insulting the caliphate.

According to the ARA News agency, the Islamic court judged he be executed in front of his distraught parents who collapsed in shock. As is common, hundreds of people were forced to watch the killing in Naeem Square, in the war-torn city.

An ARA source said: "Islamic State's police arrested Muaz Hassan earlier this week in the city of Raqqa, after they heard him "cursing divinity", while playing in the street with his friends. The act was considered an insult to the Caliphate, regardless of the age of the boy."

According to the news agency, the feared Hisba police force shot him dead a few days after they executed two young men in the city of Manbij, in Syria's northern province of Aleppo, on charges of spying for the US-led coalition, local sources reported.

On Saturday 7 May, a UN envoy said that more than 50 mass graves have been discovered in areas once held by Isis in neighbouring Iraq. The extremists massacred Yazidis, Sunni and Shia Muslims, Kurds and Iraqi troops as they carved their self-declared caliphate in Syria and Iraq.

Since Isis declared their caliphate they have publicly executed hundreds of soldiers, civilians, activists, and journalists on various charges. But observers believe that this is the first time a child has been executed for blasphemy.