Six individuals were arrested over a protest by the Extinction Rebellion environmental group inside Britain's parliament on Friday, London police said on Friday.
"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 in a statement.
Activists of the Extinction Rebellion environmental protest group entered Britain's parliament on Friday and glued themselves around the speaker's chair.
The group 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 a spokesperson for the House of Commons said the staff was dealing with the situation.
"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. We need a new way of making decisions where more voices are heard," one of the protestors inside parliament said in a video.
"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. We need a new way of making decisions where more voices are heard."
Extinction Rebellion protestor
The group also hung a banner from scaffolding on the estate and protestors padlocked themselves to gates outside parliament.
Certain areas of the parliamentary estate are usually open to the public, although access to the debating chamber is usually restricted to guided tours.
Who is Extinction Rebellion?
Extinction Rebellion, a group that has previously caused days of traffic chaos in central London, typically protest climate change issues.
Fifty people were involved in the stunt, which begins the first phase of their September plans, the group said.
They said three of the protestors had been booked on an official tour of the building.
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 country's prime minister and elected legislature regularly speak.