The so-called ’Islamic State of Iraq and the Levant’ (ISIL) terrorist group beheaded or shot 17 men in Syria in the past two days as it faces increasing attacks from unidentified gunmen in areas it controls.

The so-called 'Islamic State of Iraq and the Levant' (ISIL) terrorist group beheaded or shot 17 men in Syria in the past two days as it faces increasing attacks from unidentified gunmen in areas it controls, a monitoring group said on Friday.

The Syrian opposition Observatory for Human Rights said the spike in execution-style killings follows the killing of 10 ISIL gunmen in hit-and-run attacks in several areas around Deir Ezzor province this month.

Deir Ezzor stretches from Raqqa to the border with Iraq and links ISIL's self-declared caliphate in the two countries.

Syrian state news agency SANA said on Thursday ISIL executed three civilians and displayed their bodies in the town of al-Mayadin.