Protesters from campaign group Just Stop Oil halted an opera performance at Glyndebourne yesterday (15 June).
The BBC reports that three protesters purchased tickets for a performance of Dialogues des Carmelites at the East Sussex venue before setting off a confetti bomb and blowing an air horn an hour in.
The performance was halted for around 20 minutes while the protesters were removed from the auditorium.
A statement put out by Glyndebourne following the incident said: "We are very sorry to everyone whose visit to Glyndebourne was affected by the protest action today.
"Our highest priority was the safety and security of everyone on site and we would like to thank our staff and performers, whose calm and professional response kept everyone safe and disruption to a minimum.
"We have formally reported the incident to the police but the police were not on site and no arrests were made."
Glyndebourne has previously committed itself to halving direct carbon emissions by 2030 and reaching net zero by 2050.