More than 50 people arrested in connection with an Insulate Britain road block protest on the M25 have been released under investigation.
Officers made a total of 53 arrests following the demonstration at Junction 14, near Heathrow, on Monday morning.
Some protesters glued themselves to each other, to barriers and the carriageway, and blue paint was sprayed onto the road.
Activists, who have blocked the M25 six times in just over two weeks, continued their campaign despite a High Court injunction which could see them imprisoned, fined heavily, or have their assets seized.
The group, an offshoot of Extinction Rebellion, is calling on the Government to insulate all homes across the UK by 2030 to help cut carbon emissions.
As well as targeting the London ring road, protesters have blocked other major routes including the A1(M) and A20 near the Port of Dover.
The campaign, which entered its third week on Monday, has seen well over 300 arrests.
But the Met Police have confirmed all those taken into custody on Monday have been released under investigation.
Kent Police revealed one person was charged in connection with an earlier Insulate Britain protest, among 96 arrests made by the force.
In an open Letter to Home Secretary Priti Patel, Insulate Britain vowed to continue their campaign in the face of arrests and injunctions.
They said: “We are more fearful of the loss of our country than we are of you.
“You can throw as many injunctions at us as you like, but we are going nowhere.
“You can raid our savings.
“You can confiscate our property.
“You can deny us our liberty and put us behind bars.
“But shooting the messenger can never destroy the message: that this country is going to hell unless you take emergency action to stop putting carbon into the air.”
National Highways, which was granted the injunction, and the Department for Transport, have been contacted for comment.