The battle to retake the Islamic State (Isis)-held city of Mosul has entered its 10th week, as reports of civilian suffering mount.

A hospital in the Kurdish-control Erbil is at full capacity, Reuters reported, treating victims of both IS attacks and US-led coalition airstrikes. The exact number of dead and wounded in the offensive so far is unclear, as the Iraqi government does not release statistics on casualties.

When the battle began, aid agencies feared thousands would be leaving the city and seeking refuge in the already crowded camps, which now host overall around 100,000 people displaced by the fighting.

A large part of the 1.5 million people living in Mosul is thought to have remained in the city, either following advice from government leaflets dropped on the city or simply forbidden from leaving by IS militants, who use the civilian population as human shields.

According to Jassim al-Attiyah, Iraq's deputy minister for migration and displacement, there are more than 150,000 people internally displaced within the city, reportedly moving from one neighbourhood to the other in search of food or to escape the bombardment. Those who have remained in their homes are also in need of aid, the Washington Post reported the minister saying.

Even in areas liberated by the coalition of Iraqi, Kurdish Peshmerga and international forces, the situation for civilians remain dire. The local radio Alghad has been receiving numerous reports of lack of food supplies, electricity, heating resources, medicine, and also attacks from Isis rockets hitting civilians in those areas.

Mosul offensive
Displaced Iraqi's from Bajwaniyah walk towards security forces after being liberated from the Islamic State Ahmad al-Rubaye/ AFP

The latest delivery of food and basic supplies was carried out on 9 December to suburbs in eastern Mosul, reaching around 42,000 people in an operation coordinated by three United Nations agencies, the World Food Programme (WFP), the UN Children's Fund (UNICEF) and the UN Population Fund (UNFPA).

The delivery of aid is irregular, and dependent on the security conditions: the one in December was the first in over two weeks, the UN noted in a statement. WFP provided six-days' worth of ready-to-eat food supplies, UNFPA provided dignity kits for women, and UNICEF delivered one month's supply of water purification tablets, high-energy biscuits, jerry cans, baby hygiene kits and leaflets with information on child protection and basic mine awareness.

Lisa Grande, a UN official for the humanitarian mission in Iraq, told the Washington Post the aid agencies are worried they are going to run out of supplies: "We only have limited amounts of stocks, and if everyone near and inside Mosul requires help, we won't have enough – not by a long shot," she said.

The UN refugee agency UNHCR reported that in other Isis-controlled areas food supplies are running low, forcing civilians to make a perilous journey through mine-filled territories to reach the refugee camps in Kurdish areas, like the Laylan camp in Kirkuk.

"No one would be crazy enough to walk for three hours in the night but we had to – we were hungry. We had to cross through areas with mines," Iraqi mother Iqbal Qalaf told UNHCR workers after arriving at the camp, south of the city of Kirkuk, from the Isis-held town of Hawija, around 66km (40m) away.