UK police arrested two people on Wednesday after environmental activists sprayed an orange substance on Stonehenge, the renowned prehistoric UNESCO world heritage site in southwest England.
The Just Stop Oil protest group said two activists had "decorated Stonehenge in orange powder paint" to demand that Britain's next government legally commit to phasing out fossil fuels by 2030.
Footage posted on social media showed activists, wearing "Just Stop Oil" branded T-shirts, spraying a cluster of the megalithic standing stones with the orange substance from a small canister.
The group said Niamh Lynch, a 21-year-old student, and Rajan Naidu, 73, had used "orange cornflour" for the stunt.
It claimed the substance would "soon wash away with the rain". English Heritage, the public body which manages the site, said its experts were probing "the extent of the damage" to the circle of stones some of which are believed to date back 5,000 years.
Wiltshire Police said in a statement that it had arrested two people following the incident.
"Officers attended the scene and arrested two people on suspicion of damaging the ancient monument," the force added.
"Our inquiries are ongoing and we are working closely with English Heritage."
'Disgraceful'
Footage of the stunt showed several people trying to restrain the pair as they sprayed the standing stones, before the duo stopped and remained sat on the ground.
An English Heritage spokeswoman called the protest action "extremely upsetting" but noted the site remained open to the public.
"Our curators are investigating the extent of the damage," she said.
The incident comes in the middle of the campaign for a general election on July 4. It drew condemnation from the leaders of Britain's main political parties.
Prime Minister Rishi Sunak called it "a disgraceful act of vandalism to one of the UK's and the world's oldest and most important monuments".
"Just Stop Oil should be ashamed of their activists," he added.
Labour leader Keir Starmer, who polls predict will be the next prime minister, said it was "outrageous" and branded Just Stop Oil "pathetic".
"Those responsible must face the full force of the law," he added, in a sentiment echoed by Ed Davey, leader of the centrist Liberal Democrats.
'Resistance'
Just Stop Oil, formed in 2022, wants an end to new oil and gas exploration in the North Sea off the UK's east coast.
It has staged numerous protests, primarily aimed at disrupting events, institutions or aspects of daily life, leading to thousands of its activists being arrested and scores jailed.
The latest action was staged on the day before the Summer Solstice festival, when crowds gather at Stonehenge to celebrate the northern hemisphere's summer solstice.
A spokesperson said that although the Labour party, which is expected to win next month's election, has vowed not to issue any new oil and gas drilling licences, "we all know this is not enough".
"We have to come together to defend humanity or we risk everything. That's why Just Stop Oil is demanding that our next government sign up to a legally binding treaty to phase out fossil fuels by 2030," the spokesperson added.
"Failure to commit to defending our communities will mean Just Stop Oil supporters... will join in resistance this summer, if their own governments do not take meaningful action.
"Stone circles can be found in every part of Europe, showing how we've always cooperated across vast distances -- we're building on that legacy."