Aggression

My son was stalked and attacked in the super market by another child (around 10yrs old).Whilst my dh and dd had gone to another aisle this all happened in 2-3Min's, alhamduilah his karate training came in handy and he was able to defend him self. Now since i have returned i have noticed when my son is out with me other children looking at him in an aggressive way and almost provoking him to confrontation, my son is a is raised by me and is mashaallah a very kind and caring soul. At first i though i imagine it but no he told me sometimes when i turn my back the other boys stick their fingers up with a V sign not meaning peace. Now this angers me as its provocation, they are forcing him into trouble. what is this British Society like, what with a recent http://www.mailonsunday.co.uk/news/article-1047592/Help-help-pleaded-boy-clung-balcony-falling-seven-floors-death.html pointless murder of a young life and the countless stabbings here in the Capital LONDON, suddenly i am worried for my son and he is only 9yrs old. Anyone else experience something similar? what do you do in this society i want to know if the other mothers with boys have experience this?