The voice recording has been released on a website loyal to Saddam’s ousted Ba’ath Party, and is said to have been made by 72 - year - old former Iraqi Vice President Izzat Ibrahim al - Douri, who remains at large following the US - led invasion of Iraq in March 2003.
The 15 - minute tape asks the people of Iraq to join ISIL and contribute to the freedom of Iraq to the extent of their ability.
The message also describes the Takfiris as heroes and praises their offensive against the Baghdad government.
The crisis in Iraq escalated after Takfiri ISIL terrorists took control of Mosul on June 10, which was followed by the fall of Tikrit, located 140 kilometers(87 miles) northwest of the capital.
The ISIL has vowed to continue its raid toward Baghdad. Soldiers of the Iraqi army have been engaged in heavy fighting with the militants on different fronts and have so far been able to push back militants in several areas.
Many Sunni and Shia leaders worldwide have condemned the ISIL’s anti - Islam acts, including murder and rape.