Climate change protesters caused a disturbance at a military parade in London at the start of celebrations for Queen Elizabeth's Platinum Jubilee on Thursday, running out in front of marching soldiers before they were arrested.
The activists ran out from behind barriers where tens of thousands of people had gathered on The Mall, the grand boulevard that leads to Buckingham Palace, and lay down in front of a marching band, television footage showed.
One of the people appeared to hold up a banner, before police dragged the protesters away. One of the protesters wore a gold crown on his head.
"Today we have made 12 arrests for obstruction of the highway. This follows an incident this morning where people attempted to enter the ceremonial route on The Mall," police said on Twitter.
"Thank you to the crowd who showed their support by clapping our officers who returned to their post after dealing with the incident swiftly."
The Animal Rebellion group, which says it uses "non-violent civil disobedience to help the transition to a plant-based food system", said its activists were involved.
One of the protesters, who was filmed being detained by the police, said he wanted the royals to rewild the crown estate and stop using it for animal agriculture. He did not give his name.
The Trooping the Colour military parade, which takes place annually to celebrate the queen's official birthday, involves some 1,500 soldiers and officers. This year the parade kicked off four days of pageantry and parties to mark the queen's 70 years on the throne.
Elizabeth used to take part in the parade herself on horseback until 1986. In 1981, a man fired six blank shots at her as she rode by, but the queen managed to control her startled horse. She was unharmed and the man was arrested.