Iraq's Shiite militia has vowed to answer call of Jihad against the rising influence of Islamic State (ISIS) Sunni Militant group.Reuters

Iraq's Shiite militia has vowed to answer a call of jihad against the rising influence of Islamic State (ISIS) Sunni militant group in the city of Samarra.

Iraq's most powerful Shiite cleric and political leader, Moqtada al-Sadr, has kept his militia on alert to go into battle against the ISIS militants who seized Samarra two days ago. The city is home to a Shi'ite mosque whose destruction eight years ago plunged the country into sectarian war and the ISIS occupation of the city is likely to trigger a bloodbath in the region again.

On Friday, the Iraqi army – with the full support of the Shiite militia – liberated two key districts in Samarra as fierce clashes raged between government armies and ISIS terrorists. Local reports suggest at least 15 members of the ISIS outfit, including a top leader, were killed in fierce clashes.

Iraqi forces, along with the Shia volunteers and some Sunnis with no affiliation with the terrorists, have pushed the ISIS militants out from the Mukayshifah neighbourhood as well as the Mutassim district – both important areas of the city.

This comes after Sadr's office made an announcement earlier that his militia was forced to respond to the "exceptional conditions and imminent danger to the sacred city of Samarra from the legions of terrorists."

Sadr ordered fighters of his Shi'ite 'Peace Brigades' to be "fully prepared to answer the call of jihad within 48 hours", according to a statement dated 10 December.

Samarra is controlled by the Iraqi army as well as several Shi'ite militia who have, over the past, spearheaded the Shi'ite-led government's battle against Islamic State, which has captured a swathe of land north of Iraq and Syria.