Two members of the Brecon and Abergavenny affinity group were held for hours in sweaty police vans on Friday after being arrested during the Extinction Rebellion protests in central London.The vans were wedged in, unable to move because of the pressure of the crowds at Oxford Circus. It meant they could not be taken to police cells in the West End.

Janet Barker from Llangammarch Wells and Justin Preece from Hay-on-Wye were arrested after the Met police stepped up its efforts to move Extinction Rebellion protesters from the junction on the iconic shopping street in London.

It brings to five the total of Brecon and Abergavenny affinity group members who have been arrested since the start of the protests last Monday.

They join Sadie Stanton from Brecon, Rob Proctor from Abergavenny and Sian Cox from Llangorse who were arrested earlier in the week.

More than 800 people have now been arrested by police at the protests which have seen climate change protesters occupy Oxford Circus, Marble Parliament Square and Waterloo Bridge. Some protesters have also targeted Heathrow Airport.

Janet and Justin were kept in the police vans for several hours in the hot temperatures on Good Friday because of the pressure of the crowds. Eventually when the vans did move they were taken to police cells at West End Central police station. Janet was released quite quickly but Justin was held for more than 24 hours before being released at 5pm on Saturday because of the sheer numbers of protesters being dealt with. According to Sian, Justin was hungry when he was released but was unable to find sustenance straight away because the Extinction Rebellion arrestee support system had run out of food after having to feed so many people. Justin was arrested after supergluing himself to another protester. Most protesters are being arrested for refusing to leave a public highway or not moving after police have declared an area one where the public are not allowed to be. Following Justin's release Sian added, "he was treated well (by the police) as we all have been."In fact Justin found he had more in common with the arresting officers than he expected as some had been drafted in from South Wales Police. While being carried off along Regent Street by five police officers, Justin found himself engaged in a conversation in Welsh with a police officer who was a fellow Welsh speaker.

Sian, a 54-year-old mental health and addictions worker who was released from her cell at Belgravia Police Station at 8.30am on Friday, said she had left her spot in the Oxford Circus and spent the weekend at Marble Arch.

She said police had increased the pressure on demonstrators to leave Oxford Circus on Friday after a big pink boat had become the focus for revellers and sightseers as well as Extinction Rebellion protesters.

Sian said she had seen Emma Thompson, the English-born Hollywood actress who had taken up a berth on the pink boat, but did not get to speak to her.

Asked by the B&R Express about reports the actress had flown more than 5,000 miles to be at the protest, Sian said: "This (climate change) is much bigger than any individual’s actions. We are doing this because we need massive mobilisation from the top. I’m often asked why I have an iPhone but this is so much bigger than any one person. It’s systemic. We are all part of the same system, which needs changing because of government action.

"I wanted to do this (join the protest) because it’s something I feel very passionately about. We’ve seen before, with the Suffragettes and (Mahatma) Gandhi, that governments will only respond to mass protests like this.

"Since Monday about 12,000 people have signed up to the Extinction Rebellion movement, so it’s definitely working."

She said the Metropolitan police had been allowing people to leave the Oxford Circus protest quite easily because they wanted to remove the pink boat which was becoming a "party site". But she said protesters who left weren’t being allowed to go back.

Sian added: "They wanted to remove the pink boat because it was becoming a focus for revellers who just wanted to party. They weren’t kettling us, so I decided to move to Marble Arch."

The group at Marble Arch are still blocking the roads at the western end of Oxford Street, Sian said. She added that she had heard the criticisms about the protesters being "middle class and privileged and joining the protest in their holidays". But she said she her own motivation was the fall in the number of animals and insects, such as butterflies, bats and swallows, visiting her garden.

"I’ve always felt strongly about the environment. I’ve donated money to charities and written letters to my local MP. But this is the first time I’ve been arrested for demonstrating about what I believe in."

Sian said she had hoped to get arrested a second time because those being arrested twice were more likely to be charged.

"I want my day in court," she said. "I want to be able to stand up and talk about what I believe in."

Asked whether she would see out the full two weeks of the protest, she said: "I don’t know. I never thought I would be camping again. I’m 54 - I’m too old! We’ll see."Another protester, Angie Zelter, a pensioner from Knighton, spent seven hours in a cell at Brixton Police Station after she was carried off Waterloo Bridge by police on Tuesday afternoon because she refused to move when officers asked her to.The 67-year-old immediately rejoined the protest after her release and on Thursday could be seen sat underneath a bright pink boat, donned with the words “tell the truth” which is moored in the middle of an Oxford Circus junction.