It comes despite the Metropolitan Police “proactively” arresting Just Stop Oil protesters suspected of planning action on UK motorways.
Parts of the M25 have been temporarily closed after Just Stop Oil protesters climbed overhead gantries and caused disruption on the major motorway circling London.
A spokeswoman for the group said “action has gone ahead in multiple locations on the M25”.
Motorists were urged to avoid the area and seek alternative routes while several police forces dealt with the demonstrations.
The disruption comes despite the Metropolitan Police “proactively” arresting campaigners last night suspected of planning action on UK motorways.
A total of 23 people have been arrested so far.
Metropolitan Police Assistant Commissioner Matt Twist said the action was “criminality”, not protest, and pledged to bring those involved to justice as quickly as possible.
He told journalists on Monday: “This was a very significant and co-ordinated effort to cause massive disruption to the entirety of the M25.”
Surrey Police said a decision was made to close several sections of the M25 during the morning rush hour on Monday “for the safety of everyone” while officers removed activists.
The force said it had received reports of protesters scaling gantries between junctions 6 and 7, 8 and 9, 9 and 10, and 11 and 12.
“We are here and dealing and will get this resolved as soon as possible,” it tweeted, later adding activists had been removed and arrested for public nuisance from all those sections of the motorway, with lanes reopening.
A fifth protester, who had scaled an overhead gantry between junctions 13 and 14, was also removed – with traffic resuming
Hertfordshire Police said it was dealing with similar action on the M25 at junctions 20, 22 and 23.
“The junction 22 #M25 road closure has now been lifted. All protesters have been removed and some five people have been arrested,” the force tweeted.
Three people were arrested by Essex Police, including a man and a woman, for attempting to climb a gantry at junction 30 of the motorway. The third person had locked himself onto a gantry at junction 27.
They are now in custody and being questioned on suspicion of road traffic offences.
“At this stage, there are no longer any reported incidents on the Essex stretch of the M25 and the road has now fully reopened,” the force said in a statement.
The demonstrations took place as the latest COP27 international climate change summit in Egypt got under way.