The Metropolitan Police said a 21-year-old was arrested on suspicion of attempted murder and possession of an offensive weapon in Portsmouth by Hampshire police last Thursday.
It comes after police were called to a 16-year-old boy being stabbed in Payne Street, London, May 28. He is in a critical condition.
The man arrested in Portsmouth was later charged. He appeared at Bromley Magistrates’ Court and was remanded to appear at the Old Bailey July 1.
Several other men have been arrested.