Officers from the City of London Police arrested anti-Israel and climate activist Greta Thunberg under the Terrorism Act on Tuesday morning.
Thunberg was holding a sign reading "I support Palestine Action prisoners. I oppose genocide."
The protest took place at Aspen Insurance's offices in the British capital, denouncing its ties to the Israeli defense giant Elbit.
Thunberg protest blocks Piccadilly Circus
On Monday night, Thunberg held an additional protest at Piccadilly Circus in central London, where they prevented traffic from passing through the tourist location.
At the protest, activists, including Thunberg, shouted that they "support the hunger strikers."
Palestine Action activists began a hunger strike on November 2 due to their imprisonment for alleged offenses relating to the proscribed group. At least three of the eight detainees have since ended their strike, BBC reported on Monday.
"At around 7 a.m. this morning hammers and red paint were used to damage a building on Fenchurch Street. A man and a woman have been arrested on suspicion of criminal damage. They glued themselves nearby and specialist officers are working to release them, and bring them into police custody. A little while later, a 22-year-old woman also attended the scene. She has been arrested for displaying an item (in this case a placard) in support of a proscribed organisation (in this case Palestine Action) contrary to Section 13 of the Terrorism Act 2000," a City of London Police spokesperson was cited by The Daily Mail as saying.