All senior leaders of Islamic State (ISIS) reportedly must gather in Iraq in order to choose a potential successor for the organization’s current leader Abu Bakr al-Baghdadi.

A Syrian human rights organization based in London citing informed sources said that ISIS leadership in Iraq demanded all leaders gather, including those based in Syria, such as the army commander of greater Syria and Raqqa.

The Syrian organization for human rights has been considered a reliable source for information about the Islamic State and was one of the first organizations to report the assassinations of several prominent ISIS leaders, most of whom were killed in coalition air attacks.

It remains unclear why the organization is searching for a successor to Baghdadi. While some speculate that the leader was killed in a Mosul offensive which started in October, some believe the leader is alive but in mortal danger.