Resume de l’article : Belgique: Greta Thunberg arrêtée à Bruxelles lors d’une manifestation

Greta Thunberg, the Swedish environmental activist, was arrested in Brussels during a climate protest. According to the article, she was detained by the police for blocking a street, but was released a few hours later. The protest was part of a larger movement called « Youth for Climate, » which is demanding that the Belgian government take stronger action to address climate change. In response to this incident, Thunberg stated that « it is better to break the law than to break the planet. » Therefore, the answer to your question is: Yes, Greta Thunberg was arrested in Brussels during a climate protest, but she was later released.