Isolated in their houses and short of food and water, people besieged in the Isis-held Old City of Mosul say it is like being held in an underground prison with little idea of the ebb and flow of the battle being fought around them.

Iraqi government forces have advanced up to the periphery of the Old City, a mediaeval warren of narrow alleys and close-packed housing, but have not penetrated far into it. Whole units are prevented from advancing by two or three Isis snipers who shift their positions from house to house using holes cut through the walls so they are invisible to aerial reconnaissance. Isis has draped tarpaulins over alleys for the same reason.

Omar, a 39-year-old resident of the Old City, told The Independent that the last lights were going out in houses on his street because they had no fuel left for the neighbourhood generator, even if they could get to it.

“This is the last call I can make because nobody can go out to turn on the generator and there is no petrol, so there no way of charging my mobile after this call,” Omar shouted over a feeble phone link to east Mosul on the other side of the Tigris River, in an appeal for help. He said that nobody had any idea what was happening in their neighbourhood because of the proximity of the fighting. “I am with my family in my neighbour’s house, which is fairly big and contains about 35 people,” says Omar. “Children are crying from hunger and we have run out of the flour. We have only wheat and bran that we put some in water to become soft and give it to the children.”

Omar describes what life is like for many of the estimated 400,000 people the says still populate the Old City, who are not able to escape and cannot find out what is happening around them. “We hear explosions and shooting from outside. but nobody knows who is fighting,” he says. “An old woman joined us in the house yesterday and said that nobody is fighting [nearby] and the army has stopped advancing in the Old City.” This may well be true of the Federal Police who are stalled in the south, but the elite Golden Division has begun an attack from the west. The plan is to make multiple assaults on different fronts so the outnumbered Isis forces – figures for their numbers range from 1,000 to 4,000 – will be unable to withstand all of them at the same time.

“We have been stranded for four days,” says Omar. “We know from the people in Yarmuk district that the army is fighting there, but in our district, which is surrounded by the Federal Police, no advances have happened for more than a week. The closest street to the house where we are sitting is Faruk Street. We can hear the sounds of the explosions and air strikes and yesterday we felt as if it were an earthquake. The explosion was huge and we could hear the screaming of people outside, but no one could go out to see what is happening.”

Omar says that Isis fighters last week forced people to evacuate their houses and instructed three or four families gather in one house. They then take over the houses and make their holes in the walls to avoid using roofs or appearing in the alleys where they might be spotted. A further cause of fear is that residents do not know which houses Isis has booby trapped.

“The Old City is like an underground prison,” concludes Omar. “Anyone who enters it will be lost, and the one who escapes from it is a new born baby.”

Iraqi forces launch push to retake western Mosul from IS

As well as their houses, people are faced with the likely loss of any vehicles they may own. Omar says that “my cousin Adnan lives in Hay 17 Tamouz district, but people there are suffering from Daesh (Isis) who take their cars by force or pay little money for them, even if the car is expensive. He says that Daesh took many cars from their district and they are turned into car bombs and sent to destroy the tanks and vehicles of the Iraqi Army in Yarmouk and Al-Zinjili districts.” Adnan said that when Daesh took his neighbour’s car, they told him that "when we [Isis] conquer Baghdad we will pay you or, if the infidels win the battle, they will compensate you."

Nobody knows how long the battle for Mosul will go on for now, with many Iraqi soldiers saying that it will be at least a month and possibly much longer. Isis snipers are skilled and well hidden, often shifting their firing positions, so when Iraqi soldiers think they have located them, they use heavy rockets to try to kill them or call in air strikes or artillery fire.