I’m uncertain what is happening, hence the question mark.
The similarity with the Rangers-Celtic bigotry is that it appears to have begun with sports rivalry, in this case cricket.
I expect that partisan tit-for-tat reporting may confuse getting an understanding of what is happening.
Middle East Eye which is predominantly a Muslim-leaning website blames Hindutva militants and the Indian High Commission, claiming they are a proxy for the BJP/RSS
https://www.middleeasteye.net/opinion/uk-leicester-riots-civil-war-hindu-nationalism
The truth will trickle through eventually