An Islamic State fighter has publicly executed his own mother for asking him to leave the Raqqa-based Sunni militant outfit, said reports.

The Syrian Observatory for Human Rights reported that 20-year-old Ali Saqr al-Qasem shot his mother with an assault rifle in front of hundreds of people near the post office building, where she used to work.

Ali had reportedly informed the Isis authorities that his 45-year-old mother Lena al-Qasem had "incited" him to leave the Islamic State and escape from Raqqa together.

She had also told him that the US-led coalition will kill all the members of the Islamist terrorist group, reported the London-based SOHR.

After turning in his mother, Ali was reportedly given the task of executing her. Though the reason behind the act is unclear, some reports suggest that the intention was to give a warning to people who are trying to escape the Daesh.

The Islamic State has executed several hundreds of people in Syria since June 2014 over apostasy, homosexuality and other reasons.