CAIRO — Arab military chiefs will meet this week in Cairo to discuss the forming of a joint military force to fight the region's growing extremist threat, an Arab League official said Sunday.

After Arab League leaders agreed to create such a force at a March summit in Egypt, army chiefs from member states will hold talks on Wednesday on details of how the force will be created, its role and its financing, a League source told AFP.

President Abdel Fattah al-Sisi pushed for the creation of the force after the Islamic State organization executed a group of Egyptian Coptic Christians in Libya in February, prompting retaliatory air strikes from Egypt.

The plan gained further momentum after Saudi Arabia and several Arab allies launched air strikes on Iran-backed Shiite Huthi rebels in Yemen.

IS has emerged as the most brutal extremist group in the region, carrying out widespread atrocities and winning the support of several other jihadist organizations.

On Sunday it released a video purportedly showing the execution of some 30 Ethiopian Christians captured in Libya.