Youngsters who witness family violence are more likely to get excluded from school, carry a weapon or seriously harm someone, a children’s charity has warned.

The NSPCC said the latest Department of Education figures show 20 secondary school children in Bradford were permanently excluded and 3,250 secondary and primary schools pupils were suspended one or more times in a year as it published a report showing a “clear link” between students with violent home lives and those with behavioural problems.

Councillor Ralph Berry, Bradford Council’s executive member for children’s services, said the charity’s findings told a “familiar story” and he believed more could be done to help troubled youngsters.

“It is easy to underestimate the emotional damage done to children that are exposed to conflict at home – whether it’s hearing about it, knowing about it or witnessing it,” he said.

“Bradford has a pretty good track record for providing counselling and support for children living with domestic violence but we can always do more.”

The charity’s study found children who witness violence at home are four times more likely to carry a weapon or seriously harm someone and two times more likely to be excluded from school.

The research also revealed they were three times more likely to take drugs, steal, spray graffiti or bully others than their peers.

Stuart Herdson, Bradford branch secretary of the Association of Teachers and Lecturers, said excluding children from school was always a “last resort” and it was important school staff acted early to stop any trouble escalating.

Mr Herdson said: “If children see violence at home it becomes the norm for them. Children can get frustrated and may lash out at others.”

Gordon Ratcliffe, NSPCC head of region Yorkshire and the Humber, said even if children are not physically harmed themselves, they can still be affected.

He said: “This is something we have always known but these figures give us strong new evidence of a correlation.

“The damaging impact of family violence on children’s behaviour and education is immense. These children are acting out their emotional disturbance by causing harm to themselves or others.”