From BBC News :
Det Supt Mirfield said it appeared the attackers had made attempts to disguise their appearance.
He said: "I don't want to speculate on what colour they may have been or the nature of their ethnicity.
"Isiah was walking along the road with his brother when he was attacked by these people. The motive for the attack is unclear."
UPDATE - who else but the Pub Philosopher joins the dots.