The 40-year-old was arrested after an incident at an Islington address around 5.25am, in which police and paramedics attended.
Authorities are investigating the scene in Garratt Lane, Wandsworth where four people were injured in a suspected gas explosion.
Farah, 26, was found in the early hours of Saturday morning suffering from gunshot wounds
The incident occurred after a failure in the points system caused a South West Trains service to collide with a Network Rail wagon
Police officers were called to Chingford on Wednesday evening after reports of a woman being assaulted in a hate crime, and are now appealing for information
The eventl, which attracts more than a million people annually, began yesterday and ends today