They tweeted: “Last night we tried to have a peaceful vigil to mourn Sarah Everard. Instead we were brutalised by the colleagues of the man suspected of her murder.
“Join us for another vigil tonight @ 4pm, New Scotland Yard. We will not be intimidated. Do not dare lay your hands on us tonight.”
Tensions escalated as police tried to clear the people from the area.
Four people were arrested as supporters shouted: “Arrest your own!”
Ms Everard’s story has sparked fierce debate about women’s safety after she went missing on March 3.
The marketing-executive walked through Clapham Common on her way back from a friend’s house before disappearing.
Couzens appeared at Westminster Magistrates’ Court on Saturday morning following his arrest on Tuesday.
Chief Magistrate Paul Goldspring remanded Couzens in custody to appear at the Old Bailey on March 16.
On Monday the Police, Crime, Sentencing and Courts Bill, is due to be debated in the Commons.
The bill would give powers to police to impose conditions on protests which are “noisy” enough to cause “intimidation or serious unease” – or which have an “impact” on the local community.
Labour has announced it will vote against the Government’s key crime legislation because it is a “mess” which could lead to harsher penalties for damaging a statue than attacking a woman.
Shadow justice secretary David Lammy said the Police, Crime, Sentencing and Courts Bill contains “poorly thought out” proposals which would impose disproportionate controls on the right to protest.
He said: “The tragic death of Sarah Everard has instigated a national demand for action to tackle violence against women.
“Now is the time to unite the country and put in place long overdue protections for women against unacceptable violence, including action against domestic homicides, rape and street harassment. And we must tackle the misogynistic attitudes that underpin the abuse women face.”