London police arrested six individuals after the Extinction Rebellion environmental group staged a protest inside Britain's parliament on Friday, while it was not in session, gluing themselves around the speaker's chair.
Four protesters who were present in the chambers of the House of Commons were "de-bonded" and arrested with no damage to the speaker's chair, police said.
Two others - one who had climbed onto scaffolding outside parliament and another who had glued himself to the pavement inside parliamentary premises - were also arrested.
Extinction Rebellion had posted a photo on Twitter showing five people inside the House of Commons debating chamber holding banners reading "Let the people decide" and "Citizens' Assembly now".
Parliament is not currently sitting, and the protest comes days before a new prime minister takes office.
Certain areas of the parliamentary estate are often open to the public, although access to the debating chamber is usually restricted to guided tours.
"We are in crisis and what goes on in this room every single day makes a joke out of all of us, we cannot afford to go on like this," one of the protesters inside parliament said in a video.
The protesters were "demanding a representative democracy to decide on climate and costs," the group said on Twitter.
The incident is likely to raise security concerns around how visitors to the estate, who are routinely screened by guards upon entry, were able to access the room in which the prime minister and elected legislature regularly speak.
"A police investigation into the incident is now taking place in close liaison with our Parliamentary Security colleagues to establish the full circumstances of the incident," police said.
The action was the latest by Extinction Rebellion, a group that has previously caused days of traffic chaos in central London in protests demanding more urgent action to counter climate change.
The group said 50 people were involved in Friday's stunt, which kicked off the first phase of their September plans.
They said three of the protesters had been booked on an official tour of the building.
(Reporting by William James, Farouq Suleiman and Sachin Ravikumar; editing by Jonathan OatisEditing by Andrew MacAskill, Alistair Smout and Frances Kerry)
