2 of the blacks look like definite roos, the other 3 chicks look like roos, but could still potentially be girls, in my opinion you should wait till they are 10 or 12 weeks, then post pics again.
hi, thanks a lot for all your replies.
Just an update, the brown one and the first one (black) from the left in the bottom pic have gone to the farm yesterday. They are 120% roosters as told by the guy who picked them up yesterday.
He was not sure of the other three, so I would keep them for 2-3 weeks more, will post more photos when they are 12 weeks old.
Thank you for all your help.