Extinction Rebellion protest at Three Counties Showground
Dozens of climate change protesters blocked gates at a defence and security trade event in Worcestershire.
Extinction Rebellion, campaigning at the Three Counties Showground in Malvern, said military emissions were "seldom highlighted in discussions about the climate emergency".
Four entrances were blocked by protesters using a variety of tactics until 17:00 GMT on Thursday.
Organisers had contingency plans in place, the venue said.
According to Extinction Rebellion, between 60 and 70 people protested at the site which was hosting the Three Counties Defence and Security Expo.
Some were locked into heavy concrete blocks in front of gates while others were chained together with their arms inside heavy steel pipes. Some sat atop bamboo structures placed at entrances.
It was part of a "series of actions" in Glasgow and elsewhere during the COP26 global climate summit, the group said.
Spokesperson Suzanne Savage said Extinction Rebellion protesters were joined at Malvern by about 100 other people from different peace and climate movements in the afternoon.,
She said the public gave "a positive response", although some attending the event "were not impressed" and "used their vehicles to force their way through".
She said the group would "continue to stand up to industries".
People attending the event were forced to park in a field nearby and walk to the site.
Chris Aldridge, from the showground, said he had spoken to event organisers and "they had plans in place if this did happen", and did not think it would have any impact on visitors.
"It is a private, closed event, so it is only open to police, ministry and those businesses that are involved in cyber security," he said.
A Covid vaccination centre is also on the site. One man said he had been prevented from having his jab.
Protesters said they spoke to the vaccination centre on Wednesday and were assured it was closed on Thursday, but people attending for pre-booked appointments were let through.
The BBC has approached event organisers for comment.
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