Police were called to Uxbridge Road and Harlington Road on Wednesday (May 21) at 12am to reports of a stabbing in Uxbridge.
Two men, both aged 18, were allegedly fighting on a 427 bus.
They had stab injuries, with one of the men considered to have life-changing injuries.
However, neither of the injuries were life-threatening.
The two were arrested at the scene on suspicion of grievous bodily harm.
There happened to be a separate stabbing near the same area on the same day (May 21), at 5.45pm near to Kingston Lane and Topping Lane.
This stabbing, which occurred outside the Brunel University campus, is said to be an “isolated incident”.
A Metropolitan Police spokesperson said about the double stabbing: “Police were called at 12:00hrs on Wednesday, 21 May following reports of a stabbing in Uxbridge.
“Officers attended the scene at the Uxbridge Road and Harlington Road junction where two men had allegedly been in a fight on a bus.
“Both men, aged 18, suffered stab wound injuries in the incident, with one considered to be life-changing.
“Neither were life-threatening. They were both arrested at the scene on suspicion of GBH. Enquiries are ongoing.”
Anyone with information should call 101 with the reference 4287/21May.
