Son is being bullied

[singlemammychangingtheworld]

Hi everyone, first time posting.
Myself and my 8 year old moved into an apartment block 4 months ago. Initially, my son made a great group of friends but over the past month, 1 of them has taken it upon himself to turn on my son and turn all but 3 of the rest of the complex against him. They mock how he speaks, his hair, his clothes (I'm a single mother and while he doesn't always wear brand name clothes, hes clean and tidy). My boy is very sensitive and as a previous victim of bullying, I know how hard it is to stand up for yourself.
I checked his tablet last night and saw they had been messaging him on a video app he uses. Kids stuff but mean so its not just when he is outside.
My balcony looks out on the complex playground and while my son was in the playground with his friends, the gang of 6 (boys and girls) walked past my apartment pointing at him and telling each other what they would say and do to him.
The ringleader is not Irish and his mother claims to not be able to speak English so going to her is pointless. According to a few other Irish parents, he has targeted each one of their children when they moved it but has never gone near any of the non- Irish children. He has even gone so far as putting a knife to one of the kids and shouting obscenities at women and what he would love to do to them. Hes 10. They have gone to his parents but nothing is done. The child is petrified of me as I've let roar at him before. His voice and body language instantly changes the second he spots me but I cant follow my son around all day.
My boy is very sensitive and as a previous victim of bullying, I know how hard it is to stand up for yourself. I really don't want to encourage him to hit or slag anyone back but I don't really know how else to to advise him. Breaks my heart when he comes up crying because hes been pushed off the swing and the other kids are encouraged to tell him everyone hates him.
Any advice is greatly appreciated!

Karen

To put anything on social media regarding bullying is an offence, well sending it is the actual offence. However, it’s proof of what they’re doing. Are you private or council, housing association? If council, go to them the kids behaviour is not allowed, same for housing association, this could lead to eviction. Why not speak to the other like minded parents and complain as a group ( one kid can’t be targeted then!) this will mean that some action will be taken.
What language does she speak? I would write her a letter, google can translate into most languages on earth, and hand it to her! Or post thru door and a picture of that on your phone, explain gif she does nothing to stop this then there is a group of people willing to complain about her kids behaviour, that may lead to her and their evictions!
I’m sorry that it’s affecting your boys, tell him to turn the phone off when he’s sleeping. That will at least let him have some peace
Good luck

Its private complex. Some are owner occupied, some are rented.
They are Romanian. I don't know whether to involve the management company, maybe they might contact the landlord.

Well you could start there. Ask if they know if the Romanian family are renting or council, then choose your route. The council will also have access to translators, but since you have a phone, use google to translate for you! She talks into your phone the phone speaks to you in English! No more barriers. If you don’t fancy that translate a text message?
They are in a new country, and trying to establish who is the top dog!
Good luck