A brawl broke out at a packed shopping centre after a group of “paedophile hunters” accused a man of grooming a 14-year-old girl for sex.
Footage broadcast on Facebook Live showed the men approach him, saying: "You're here to meet a child for sex, yeah?"
The man, under repeated questioning by the group, denies their allegations.
But, as the confrontation continues, a shopper in a red top appears to attack the man, kicking and punching him as other people try to contain the situation.
At one point, the alleged attacker appears to climb on to a flower bed and start repeatedly kicking the man while hurling abuse.
Security guards from the shopping centre step in to prevent any further violence before police officers arrive.
Detective Chief Inspector Emma Banks, of Kent Police, said a 29-year-old man had been arrested on suspicion of grooming and officers were investigating the disturbance.
She said: "Officers from Kent Police arrested a 29-year-old man from east London at Bluewater Shopping Centre on suspicion of grooming at 2.27pm on April 16.
"The arrested man is in custody. Police are also investigating a disturbance which took place in connection with this incident.
"I strongly discourage people taking the law into their own hands to avoid them and others including individuals which may have been wrongfully identified, being put in any danger.
“Any acts of violence reported will always be fully investigated and enquiries into this incident are ongoing."
Additional reporting by the Press Association.