More than 46,000 people who fled Iraq's Mosul as fighting raged have returned to the eastern part of the city over the past two weeks in an attempt to restart their lives.

US-backed Iraqi government forces say they have now taken a quarter of Mosul from the Islamic State of Iraq and the Levant group, though fighting in parts of the east continues. ISIL still largely controls the western side of city, which is divided by the River Tigris.

Al Jazeera's Osama Bin Javaid, reporting from the outskirts of Mosul, said that people were determined to return despite the risks.

"They prefer to go back home rather than staying .. in camps .. or with extended family," he said. "ISIL propaganda has showed recent drone hits and mortars being fired towards areas now under Iraqi control. Many here feel air strikes and shelling have caused most of the damage to their city."

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Social media was being used to mobilise returning residents to rebuild the city.

"In many neighbourhoods, cleaning campaigns are being organised, but with so much destruction and so little money, they can only do so much," Javaid said.

The United Nations said on Wednesday that it was temporarily halting aid operations to neighbourhoods in the east that are under constant attack from ISIL fighters.

UN Humanitarian Coordinator for Iraq, Lise Grande, said UN agencies had "made the decision that until security improves it will be difficult for us to provide assistance."

While life is resuming in some eastern Mosul neighbourhoods, more than 140,000 people are still displaced and hundreds of thousands are trapped in the western ISIL-held part of the city as fighting continues.

Preparations are under way to launch an offensive on the west, which is expected be more difficult because of the density of the population and the narrow streets and alleyways through which armoured vehicles cannot pass.

Last month, the UN World Food Programme cut food rations, which are distributed to 1.4 million displaced Iraqis, by 50 percent because of delays in payments from donor countries. The impact is already being seen in camps east of Mosul, which is ISIL's last major stronghold in northern Iraq.

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ISIL is now intensifying attacks in government-held parts of the east, and government security forces are conducting house-to-house searches to find its sleeper cells.

Mosul is still home to nearly 1.5 million people, many of whom are trapped by the fighting.