More needs to be done to help up to 2,000 children who are locked up in the UK's immigration centres every year, according to a group of charities.
Current government figures don't show how many kids go into the centres, but information gathered by the charities estimates there are 2,000 each year.
The Refugee Council, Save The Children and Bail for Immigration Detainees said this was "inhumane and unnecessary".
A government spokesman said kids in the centres were looked after.
He explained that if families were detained for more than three days, they were moved to the Yarl's Wood centre in Bedfordshire, which has activities for children and teaching facilities.
The length of time kids spend in the centre varies, but it's unusual for them to be there for more than a month.
They can be taken to the centres for a variety of reasons, such as if their claim for asylum is being investigated or if their family's claim has been rejected and they're waiting to be sent home.
The charities want the government to say exactly how many kids are in the centres.
The government spokesman said the way the figures were being released was changing so "we will be able to present a picture of how many children are detained each year".