ISIS executed over 4,000 in Syria in last two years: Report

The Islamic State militant group has executed over 4,000 people within two years, a UK-based Syrian Observatory for Human Rights (SOHR) said, calling on the UN to stop the crimes and violations committed against the Syrian people by the outfit.

Monitors compiled the list dating back to the declaration of ISIS in June 2014, showing regular beheadings, shootings, stonings and other methods of murder such as throwing people off buildings and setting them on fire.

The so-called offences of those executed included sodomy, apostasy and alcoholsmuggling, SOHR notes.

It concludes that by the end of the 22nd month of the so-called "caliphate" under ISIS, 4,144 people had been executed.

SOHR said civilians made up the bulk of those executed, estimated at 2,230 people, including in three large-scale massacres of Sunni and Kurdish citizens.

The civilians, including women and children, are among the number, as are hundreds of ISIS' own members and enemy fighters from Bashar al-Assad's army and opposition rebel groups, 'The Independent' reported.

"The Syrian Observatory for Human Rights call again on the UN Security Council to work seriously to stop the crimes and violations committed against the Syrian people by the 'Islamic State' and the regime of Bashar al-Assad," a spokesperson said.

In the month until March 29 this year, 80 killings were recorded in ISIS territory in the provinces of Deir ez-Zor, Raqqa, Damascus, Aleppo, Homs and Al-Hasakah.

A child was among 37 Syrian civilians executed, while 24 ISIS members, six rebels and fighters and more than a dozen Syrian army and militia members were beheaded and shot, SOHR said.

A former London student who joined ISIS in Syria last year described the reign of terror they enforce in their strongholds in an interview with the newspaper.

"I witnessed stonings, beheadings, shootings, hands chopped off and many other things," said Harry Sarfo, currently in prison in Germany awaiting trial for terror offences after fleeing Syria last July.

He added: "I've seen child soldiers - 13-year-old boys with explosive belts and Kalashnikovs. Some boys even driving cars and involved in executions."

"My worst memory is of the execution of six men shot in the head by Kalashnikovs. The chopping off of a man's hand and making him hold it with the other hand," he said.

"The Islamic State is not just un-Islamic, it is inhuman. A blood-related brother killed his own brother on suspicion of being a spy. They gave him the order to kill him. It is friends killing friends," he added.