Coalition forces are backing local government and Kurdish military with air strikes in an attempt to take Mosul, the country’s second largest city, back from IS rule.
Safe escape routes out of the city for civilians caught up in the bloody conflict “do not exist”, Save the Children has warned.
Families and children have been advised by local forces to stay inside and erect a white flag on their homes in a bid to stay safe, the charity’s spokesman, Ruairidh Villar, said.
Speaking from Irbil, he said: “Whether families and children stay or they flee, right now it’s an impossible decision.”
Save the Children, which said humanitarian agencies are able to get no closer than 30 miles to the city, is calling on people to urge the Government to do what it can to ensure there are safe pathways for people to leave the area.
He said: “We are calling on the UK Government to put pressure on the Iraqi and coalition forces around Mosul now to establish safe corridors, safe escape routes for children to get out.”
Children in Mosul, which has been under IS control for two years, face further trauma amid the bombardment of the city, Mr Villar said.
“These children have been through two years of IS rule, subject to an education which is focused on extremist violence,” he said, adding that much planning has gone into military operations but not necessarily the humanitarian fallout.
“Some children have not gone to school at all. There’s been a lack of food and medicine and after all that they’re going to have to escape from what looks to be a very bloody conflict indeed.”
The charity said the UN’s emergency appeal is not well enough funded, meaning camps only ready to house around 60,000 people could be “overwhelmed within days”.
Save the Children is providing emergency water supplies, dried food, soap and other items to newly displaced families, and has appealed to people to donate to their campaign to help those affected.
The Government has said the creation of such safe passages for civilians “hinges entirely on the good will of all parties to the conflict” and said this is unlikely where IS, also known as Daesh, is concerned.
A spokesman for the Foreign Office said: “In the case of Mosul, the Iraqi Security Forces will facilitate the transportation of civilians fleeing the city to locations outside of the conflict zone, where they can be sheltered and assisted by the UN and other humanitarian actors, as they did successfully in Fallujah.
“’Safe areas’ and ‘humanitarian corridors’, however, are unlikely to be a viable option to the context of Mosul. Daesh have never shown any regard for civilians, so it is unlikely that they would agree to provide security guarantees for civilians leaving Mosul.”
Foreign Office Minister Tobias Ellwood said: “The start of Iraqi operations to retake the city of Mosul marks another step forward towards clearing Daesh from Iraq. After two years of brutal rule, the people of Mosul can start to have hope for a better future.
“This will be the greatest challenge that Iraq’s security forces have yet encountered. They are up to that challenge. The UK, as part of the global coalition, is committed to continuing to provide the government of Iraq with military, humanitarian and stabilisation support.” Cornwall-based charity Shelterbox said not knowing which locations people might flee to creates difficulties in organising aid provision, and makes it “a matter of instinct and assumption”.
Rachel Harvey from the charity, who is in Irbil, about 85 miles from Mosul, said: “The aim is to get aid to displaced families as quickly as possible. So we are pre-positioning stock close to places where we think they might arrive. They are likely to be exhausted and traumatised by their recent experiences.
“Giving people shelter and essential items such as a solar lamp, blankets and a water carrier will allow them a degree of dignity and security to rest and recover.”