[Photos] The fight for western Mosul

Since government forces broke through the city's southern limits on February 23 and pushed into west Mosul, thousands of civilians have fled fierce fighting in ISIS-held areas, seeking medical assistance, food and water, Iraqi commanders said.

The United Nations says up to 400,000 people may have to leave their homes during the new offensive as food and fuel runs out in western Mosul.

Aid groups have warned that the most dangerous phase of the offensive was about to begin in west Mosul narrow streets.

If ISIS is defeated in Mosul, that would crush the Iraq wing of the caliphate that the group's leader Abu Bakr al-Baghdadi declared in 2014 over parts of Iraq and neighbouring Syria.