Filming was underway in Cotham as "luxury" minibuses and a marquee were spotted on a set.
A passerby spotted a film crew and "chauffeured cars and minibuses" at Cotham Park on Wednesday afternoon (April 14), with a "huge marquee" in the grounds of Muller House.
Another man in the area said: "There was filming in front of one big house, and then the marquee was in the grounds. Most of it was happening round the back, away from prying eyes.
"There were maybe 10 vehicles in total. I saw a few lighting trucks and two luxury limousine-style minibuses, which looked like 25-seaters."
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The set at Muller House - which is the base of young people's charity Mullers - was within a mile of Cotham School, on Cotham Lawn Road, which has also seen filming in recent months.
Back in February, Cotham School's car park allowed spy drama Alex Rider to shoot some scenes for the second series. It is not known whether the same show has been filming in the area this week, but a local said a crew appeared to be at the school again on Thursday.
Alex Rider, based on the books of Anthony Horowitz, follows the titular teenager who has been trained as a spy since he was a young child.
Rider is played by Otto Farrant, while Line of Duty's Vicky McClure and Game of Thrones' Stephen Dillane also feature, as members of The Department, an underworld offshoot of MI6.
The Amazon Prime production is being headed up by Eleventh Hour Films, the London-based company behind Safe House, New Blood, Collision and Foyle's War. It is being supported by Bristol Film Office.
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