A man arrested for immigration offences was released after protesters went to the scene and tried to "block" enforcement officers.
A group of people gathered in southeast London for hours to stop a vehicle that the arrested man was in from leaving.
Footage from the scene showed a crowd of people sitting on the ground in front of a van in Peckham, while another clip showed members of the public shouting "let him go" at the officers in attendance.
Officers from the Metropolitan Police were called to Evan Cook Close shortly after 1.30pm on Saturday after there were reports of "protesters obstructing immigration officers".
The man the immigration enforcement officers were attempting to detain is understood to be Nigerian and was suspected of overstaying his visa.
One activist with the south London arm of Stand Up To Racism, who gave her name only as Nicola, said police "gave up" trying to arrest people at the scene.
She said: "Police tried to arrest a number of activists at the front, but they were held onto by others who were also sitting down and the police gave up.
"And finally, after a lot of protest, the police announced that they were going to release him (the arrested man) and it took, I don't know, about half an hour for them to actually open the doors so we all stayed and called for this to happen quickly."
Authorities later said the arrested man was released on immigration bail.
A spokesman for the Met said: "Officers attended and found a van was being prevented from leaving the location.
"One man has been arrested by immigration enforcement officers for immigration offences."
'We all sat down'
Eleanor Janega said people were alerted that an immigration raid was happening "so locals came down to block it".
She added: "We had been sitting here blocking the van and having ice lollies. They brought more police in and tried to break through the crowd by pushing us. We all sat down."
Labour councillor Reginald Popoola said people who attended the scene had surrounded "the van peacefully", but claimed some people were pushed during the demonstration.
Referring to the fact the man was released on bail, Mr Popoola said: "He's being released, peaceful protest is powerful."
'Obstructing them will not deter them from undertaking duties'
A spokeswoman for the Home Office said: "Preventing immigration enforcement teams from doing their job is unacceptable.
"Blocking or obstructing them will not deter them from undertaking the duties that the public rightly expect them to carry out."
It comes amid a row over plans by the government to send more than 30 people on Tuesday to Rwanda.
The Home Office says they arrived in the UK illegally and they are being sent there to have their asylum claims processed.
On Friday, the High Court ruled that a flight taking the asylum seekers to the east African country can go ahead.
The Home Office is set to schedule more flights this year.
Rwanda has defended the scheme, asking for it to be given "a chance", after Prince Charles is said to have privately called it "appalling".