Iraqi forces advance on Mosul mosque where IS declared caliphate

Smoke billows in a part of West Mosul, where Iraqi security forces are fighting Islamic State, Iraq June 21, 2017. REUTERS/Marius Bosch

MOSUL, Iraq (Reuters) - U.S.-backed Iraqi forces on Wednesday began a push towards the mosque in Mosul where Islamic State declared a self-styled caliphate three years ago, military officials said.

The forces had encircled the jihadist group's stronghold in the Old City of Mosul, where the medieval Grand al-Nuri Mosque is located, on Tuesday, they said.