Teenagers are turning to gun crime because they are being failed by schools, the Bishop of Birmingham has claimed.
The Right Rev John Sentamu said the national curriculum had squeezed out subjects which allowed youngsters to let off steam and have fun in school.
He blamed large classes, an obsession with targets, run-down buildings and a lack of playing fields for children becoming disillusioned and opting out of education.
Dr Sentamu described how he walked around the Lozells area of the city, one of the most deprived and dangerous parts of Birmingham, in disguise to see what was going on.
"It came as no surprise to see people peddling drugs and getting involved in drug crime. They see this as a way of making money and getting rich," he said. "We need to show children that you can become rich by getting an education."
Police in Birmingham have still not caught the killers of teenagers Letisha Shakespeare and Charlene Ellis who were gunned down during a New Year party last year.
Recently it emerged that gangs in the city are being supplied with weapons by Irish Republican terrorists.
Dr Sentamu said: "I am very concerned about the rise in gun culture. We need a cure for this and that is to provide a decent education and a way out for young people.
"If we fail then these evil people will take over and wreak havoc in our communities. They are doing it already."
Dr Sentamu was speaking after he visited King Edward Camp Hill school. He said all children should enjoy the same facilities as the girls' grammar.
He said he had visited state schools in the city with run-down buildings and "nothing but concrete" for pupils to play on.
"It is not the teachers' fault. They are doing their best in very difficult circumstances.
"When you see a school like Camp Hill you know that pupils are learning there. Even if they don't want to learn they will, because the environment is conducive to it.
"Assessment targets have pushed out too many subjects in our schools. What has happened to singing and music and playing sports? Children who have fun return to the classroom refreshed and ready to work because they have let off steam.
Without that opportunity, their energy is not spent so they look for other outlets.
"The way primary schools are timetabled must be changed so that there is time for these things."
Earlier, Dr Sentamu told an audience at Camp Hill school: "When children come from homes where their parents can't quite read and can't quite write it means you need a much lower pupil-teacher ratio.
"I would have thought in some of our really difficult inner-city schools you shouldn't have more than 15 pupils per class.
"A lot of investment has to be put into that if we are to tackle the question of gun crime. It is not about more police. You have to tackle where the thing starts."
Judy Worsley, head of Lozells primary school, said she could relate to the bishop's comments. She said: "It can be difficult at times because of some of the attitudes among the pupils.
"But we serve our children by giving them a good education and telling them they can do better. We are very strong on teaching what is right and what is wrong."
Dave Walters, head of Aston Manor school, which also serves Lozells, said:
"Schools have much to offer their local communities and we are working closely together. We offer pupils a warm, supportive and caring environment where they feel valued and encouraged to reach their full potential.
"We would be delighted to welcome the Bishop to Aston Manor anytime."