Nazir has said schools were worried about pupils travelling over time . But schools educate teenagers because they do not want them placed under investigation , he said . About 600 children are believed to have undergone Islamic training since childhood .
Nazir Afzal said schools were worried about pupils travelling over holidays . But schools protecting teenagers because they do not want them placed under investigation , he claims . About 600 Britons are believed to have joined Islamic State since 2013 .