Fear and hunger are driving an ever-growing number of Iraqi civilians into a camp in Hammam al-Alil, where they share harrowing tales of deadly violence and jihadist tyranny in Mosul.

Some arrive at the displacement camp, the largest in the Mosul area, on foot, but most of them are crammed into buses and trucks, relieved and exhausted.

People are boiling paper and cartons to fill their stomachs.

Half a million people are currently displaced as a result of the massive seven-month-old offensive to retake Iraq's second city from the militant Islamic State (IS) group.

Thursday saw what the Norwegian Refugee Council said was the biggest single-day displacement since the start of the operation, with around 20,000 fleeing neighbourhoods of west Mosul.

"I feel safe, I did not think I would get out of there alive," said Shams Hassan, a woman in her forties who reached the Hammam al-Alil camp on Friday with 16 members of her family.

She is from the Al-Faruq neighbourhood of Mosul's Old City and lost track of the number of times she and her relatives had to change houses and neighbourhoods in recent months.

'Those who tried to flee were executed in the streets and their bodies hung from posts'

"They always wanted us to be in front of them to use us as human shields. They would come to tell us to change houses," she said.

"We would find ourselves in the middle of shelling and car bombs. One of the houses we lived in was struck by a mortar round, it collapsed on us and I was wounded by shrapnel. I had to be carried," she said.

A large population remains in Mosul's Old City, where IS appears to have concentrated most of it remaining resources. Some estimates put the number of civilians still trapped in west Mosul at 250,000.

'Hanged from posts'

Human shields have become a central feature of the vastly outnumbered militants' defence and IS has stopped at nothing to deter people from escaping the city.

"Those who tried to flee were executed in the streets and their bodies hung from posts," Shams Hassan said.

Her mother, who reached Hammam al-Alil a few weeks earlier, sat next to her, her gaze lost in the distance.

'We fled death only to face death here... Take us home, it is better for us,'

"Daesh would take our food," the old lady said, using a derogatory Arabic acronym for the militant Islamic State group. "They would come with their guns and take our clothes too." Trapped residents reached by AFP inside the areas still controlled by the IS have warned recently that hunger was beginning to kill more people than the intense fighting itself.

There is no clean water left to drink and even unclean water is hard to come by. People are boiling paper and cartons to fill their stomachs.

“A bottle of oil was 50,000 dinars (around 40 US dollars), a can of tomatoes was 50,000 dinars too. Flour was 5,000 dinars. We ate some of it and got sick,” said Shams Hassan.

Eating grass

"We haven't showered the kids in two months, they have lice," she said.

Having moved countless times, they eventually managed to escape when the Iraqi security forces reached their neighbourhood and escorted them out through holes that both sides have punched in walls in people's homes to move up and down blocks undetected.

"We were walking on broken glass and rubble... my son had to carry me," she said.

At age 72, Ahmed Yunis Dawood dodged sniper fire to leave west Mosul through the neighbourhood's water mains.

"For five days, I would go out at night to check out the streets," he recounted.

In the Hammam al-Alil camp he reached early Sunday, the elderly man found safety but little else.

"The people who arrive here have no tent, no bed to sleep in, no food, no water," Dawood said.

Aid groups have been delivering assistance in the camps to tens of thousands of civilians daily but the lack of funding, the recent peak in displacement and soaring temperatures are leaving many outside the relief net.

In the dusty chaos engulfing the entrance of the camp, where new arrivals are screened and in most cases subsequently dispatched to other locations, one man cried in despair.

"We fled death only to face death here... Take us home, it is better for us," he said. "An air strike will come and we will die together. We were eating grass like cows but at least we were in our homes."