Police were called to Tracyes Road, near Passmores Academy, shortly after 3.35pm on January 13.
A knife was seized and a 15-year-old boy was arrested on suspicion of assault and possession of a bladed article.
He has been released on conditional bail while the investigation continues.
A teenage victim suffered a minor hand injury not linked to a weapon.
Acting Chief Insp and Harlow district commander Leanne Archer said: “Quite clearly there will be some concern around this incident given where this has taken place.
“The response to the incident was very quick and we were able to make an arrest and ensure there were no serious injuries sustained.
“A boy was questioned in connection with the incident and has been released on conditional bail whilst this investigation continues.”
Chief Insp Archer added: “Driving down and preventing knife crime is among the most important work police officers and staff do.”
She explained that more than 50 per cent of serious knife crime perpetrators are aged between 10 and 19, with the majority of victims also male and in the same age group.
Police are asking anyone with information or footage of the incident to contact them, quoting incident 576 of 13 January.
