Dozens of Just Stop Oil supporters suspected of planning to disrupt airports this summer have been arrested across England.
The Metropolitan Police said 27 people were taken into custody, including some believed to be “key organisers” for the climate group.
All the arrests were made under a section of the Public Order Act that makes it illegal to conspire to disrupt national infrastructure.
Four people were arrested on Tuesday after being identified at Gatwick Airport and have since been released on bail.
Six were held on Thursday night at an east London community centre hosting a Just Stop Oil event “promoting airport disruption”, the Metropolitan Police said in a statement.
A total of 17 people were arrested at their homes across England on Friday morning as Metropolitan Police officers worked with more than eight other forces.
Police activity has taken place in London, Gloucestershire, Oxfordshire, Devon, Essex, Manchester, Surrey, Sussex, Norfolk and West Yorkshire.
Chief Superintendent Ian Howells, who led the operation, said: “We know Just Stop Oil are planning to disrupt airports across the country this summer which is why we have taken swift and robust action now.
“Our stance is very clear that anyone who compromises the safety and security of airports in London can expect a strong response from officers or security staff.
“Airports are complex operating environments which is why we are working closely with them, agencies and other partners on this operation.”
Suspects released on bail are subject to conditions which include not travelling within one kilometre of any UK airport unless passing by while on a mode of transport.
In response to the wave of arrests, a Just Stop Oil spokesman said: “It isn’t a massive surprise.
“I think it speaks volumes when we’ve got a police force cracking down on non-violent Just Stop Oil supporters in this way.
“The people enacting criminal damage on an unimaginable scale against all of us – oil company executives and the politicians that they’ve bought, basically – when is it that those folks are going to face the full force of the law?”
Asked about the justification for planning to target airports during the key summer holiday period, the spokesman said: “In normal times, that kind of disruption would be entirely unacceptable.
“But you can’t really disassociate what we’re potentially planning on doing from the reasons why.”
He added that disruption is necessary because people are “dropping dead around the world” from extreme heat, and “tipping points” are being passed.