Scotland Yard
Scotland Yard has been accused of sending "vague threats" to the environmental group on the basis of Covid-19 gathering restrictions – from which XR are exempt.
The arrest was described as mirroring "exactly what happened to George Floyd".
A 40-year-old man was also found injured and taken to hospital, the Metropolitan Police said.
Scotland Yard makes a "mandatory referral" to the Independent Office for Police Conduct.
Two men have been arrested on suspicion of attempted murder.
Scotland Yard has said it will not launch a criminal investigation into SPAC Nation - but one alleged victim says she has not even been contacted by detectives.
Graffiti was found on a building near to the North Brixton Islamic Cultural Centre.
The victim has been named as Swedish national Flamur Beqiri.
Police said the 36-year-old was shot dead 'just yards from his home'.
Scotland Yard has confirmed a murder investigation has been launched.