Updated

Umm Mohammed decided to flee western Mosul after her husband told her the alternative was that they starve.

Their family — six boys and a girl — had been eating little for the last three months as money ran out and supplies became harder to get a hold of in the half of the northern Iraqi city that is still under the rule of the Islamic State group.

Iraqi forces, after capturing the east in January, have been gearing up for a final assault on the west that officials say could come at any time. In past weeks, people have been slipping out of the western sector, saying a mix of poverty and low food stocks meant that getting food had become a serious problem.

"People were eating whatever they had, water with bread, or water with tomato paste," said Umm Mohammed. Her kids sometimes went to bed without even that. She and her family made it to eastern Mosul, then to a camp for displaced people outside the city.

She spoke on condition she be identified by her traditional honorific because she feared for the safety of relatives still in western Mosul.

The United Nations estimates that up to 750,000 civilians may be left in the western half of the city. Aid agencies have no access and all the commercial arteries have been blocked. Since the beginning of the year, around 140 families — some 600 people — have made it out of the west to the camps of displaced, according to the U.N.

The militants have been trying to prevent residents from leaving.

Dafr Mohammed, a 24-year-old farmer from Baddoush, a town on the northern outskirts of the city, said he arranged a boat to cross the Tigris River to the eastern side but was caught by the militants. He was only able to get out because he convinced them his wife was sick and needed a doctor — and because he left other relatives back in the west, which they took as a guarantee.

"Most nights we went to bed hungry, including the two kids," said Mohammed.

He said the problem wasn't so much the lack of food but that people had no more money to pay for it. "Daesh took all the wheat and barley we harvested this year without payment so we didn't have any money," he said, using the Arabic acronym for IS.

He survived by doing odd jobs and sometimes getting some money from an uncle who was still receiving his pension. By January, they run out of heating fuel and wood, and started burning their clothes to keep the children warm, he said.

Prices in western Mosul have skyrocketed, especially after the road to Syria was blocked late last year, because no more food was coming in, those who escaped said. A 50 kilogram (110 pound) sack of rice rose to 120,000 dinars ($95), from 19,000 ($15). A sack of flour, once 1,000 dinars ($.80), is now 7,000 ($6).

The UN's humanitarian arm said earlier this month that powdered milk for babies had become almost completely unavailable and that a lack of drinking water was also a problem.

Abdul-Rahman Aouf Aziz, a 24-year-old who fled in January, said he had got out because he couldn't handle it anymore and was prepared to risk his life in the escape.

"There was no life left there. It had become very hard," he said.