Police were called to Hendon Central station at around 8.45pm last night (September 3), following reports of a fight between a small group of people.
It was also reported that the fight involved a teenager with a knife.
At the scene, a 17-year-old boy was arrested in connection to the incident and taken to custody.
Two people were taken to hospital with injuries, which are not considered to be life-threatening or life-changing.
The British Transport Police (BTP) has clarified that neither of the victims were stabbed.
Another person suspected to be involved in the fight allegedly left the scene and was believed to have trespassed on the tracks.
Police helicopters searched the tracks between Hendon Central and Colindale station, with police dogs also deployed to the scene.
Despite the search, no one was found, the British Transport Police has said.
It is understood that Northern line services on the Edgware branch were disrupted near to Hendon Central, with passengers being forced to leave their trains at Hampstead.
Enquires are ongoing and anyone with information is asked to contact BTP by texting 61016 or calling 0800 40 50 40, quoting reference 725 of 3 September.
