A young man was repeatedly knifed near Wembley Arena after a concert by Jamaican dancehall star Popcaan.
The victim, aged in his 20s, was rushed to hospital after being stabbed five times, including three times in the chest, in north London.
Emergency services rushed to Arena Square, off Engineers Way, Wembley at around 11.45pm.
He was taken to a north London hospital where his condition is not life threatening, Scotland Yard said.
Shortly before midnight, towards the back of the venue, a 31-year-old male was arrested by police and a firearm and ammunition were recovered.
He was held on suspicion of possession of a firearm with intent to endanger life.
Officers took him a north London police station where he remains.
A Met Police spokesman said: “A crime scene is in place and officers from North West Area Command Unit remain on scene at this time.
“There were no reported injuries as result of the firearm. Enquiries continue.”
Anyone who witnessed this incident but has not yet come forward is asked to call police on 101 quoting CAD8801/6DEC, Tweet @MetCC or call the independent charity Crimestoppers anonymously on 0800 555 111.
