Nearly one million children in the UK could be living with domestic violence, according to a report by the United Nations Children's Fund, Unicef.
Children who witness domestic violence could be badly affected, says Unicef
Between 240,000 and 963,000 children in the UK have witnessed violence against a parent or caregiver, it estimated.
And it said the effects on children could range from poor exam results to them becoming violent themselves.
Home Office minister Lady Scotland said the government was making every effort to deal with the problem in the UK.
"The tragedy is on many occasions when it's happened, children will be in the house, they'll be badly affected by it.
"And what we've done, with the policies that we have, is we've tried to help professionals to understand that, they'll be able to help and do something about it."
Practical steps taken by the government included the creation of a domestic violence and bullying information pack produced by the National Union of Teachers (NUT) and the Department for Education and Skills (DfES), she said.
"The fact that people are talking about it, the fact that we're helping teachers, helping the people who will have access to the children to know how to better support them, that will make a difference and is making a difference," she added.
The figures were among the findings of a joint study with the United Nations Secretary-General's Study on Violence against Children and Body Shop International.
The report found that up to one in 14 children in the UK could have poor exam results as a result of the effects of domestic violence in their homes.
A range of effects suffered by children included aggression and low self-esteem.
It also said young people who grew up with violence were more likely to be abused themselves.
Children witnessing violence could also suffer the same effects as direct victims, the report added.
The National Society for the Protection of Children (NSPCC) said the government could go further by better educating children about issues of domestic violence and by providing counselling services for vulnerable children.
It is calling for person, social and health education (PSHE) to be made a foundation subject for all schoolchildren.
"Lessons would include information on a range of life skills, including identifying stress and conflict at home such as domestic violence," policy adviser Emily Arkell said.
"Lessons would help young people acquire the skills to cope or to access help and support."
The authors of the report - Behind Closed Doors: The Impact of Domestic Violence on Children - said it was the first global effort to document the extent of such violence.
Globally, it said, as many as 275 million children could be exposed.
Dr Amaya Gillespie, director of the secretariat of the United Nations Secretary General's Study on Violence Against Children, said more work still needed to be done.
"We are just beginning to develop a clearer global picture of the problem and are in a position to call for action by governments and communities to stop the exposure of children to domestic violence," she said.