The UN Refugee Agency (UNHCR) on Tuesday said as many as 250,000 people could be forced to flee west Mosul.

"We're extremely concerned because the fighting is expected to be extremely intense," UNHCR spokesperson Matthew Saltmarsh told reporters here.

Forces hope to recapture western parts of the Iraqi city which has been under the Islamic State (IS) control since June 2014.

"The city's western side is densely populated, with many narrow streets and fighting will be street by street. Armed groups have also built networks of tunnels," he added.

According to UN estimates, some 750,000 people are trapped in western parts of the city, whose eastern side was liberated in late January after more than 100 days of fighting against IS militants.

UNHCR warned that conditions in western parts of the city are worsening amid food, water, fuel and medical shortages.

According to reports, half of all food shops have been forced to close and most people are only able to access untreated water.

In light of the predicted exodus, the UN body said that it is focusing on camp construction to be able to accommodate as many civilians as possible.

It warned, however, that it is currently impossible to accommodate 250,000 people on existing land, and that it has "identified other land that could be used as camps once frontlines shift."

Source: Xinhua