here's the deal. There is no way that we kan know at this moment in time wether it was a racially motivated attack or not, but there are some things here to consider.
See, i agree with some of the things people have said here.
The likeliness of the "Asians" beating a fellow asian to this severity is very low. Especially for a mobile phone theft. I mean, if their friedn was severly beaten up then maybe they would, but for a petty theft such as this i don't think so. People do not beat up people from thier own race, especially when the race is an ethnic minority in that region.
That said, i think that initially the attack was not racist, however, because the victim was of a different racial background to the perpetrators, the attackers would have felt more angry, and hateful towards this person for the said reason above. Anoh=ther thing to consider, is that they beat up this kid, even though he didn't 'jack' thier phone, (thats what we know from the newspaper, for all we know he could have commited other crimes).
so all in all, we kannot condem this attack as purely racially motivated, but we kan say that race had something to do with the severity of the attack.