A police officer was injured and at least two people were detained during the most tense day in 17 days of camping in Madrid's Puerta del Sol, after radical groups tried to break up the housing protest. The trouble erupted after the National Day parade ended, when a group of people with Spanish flags, including some described as unconstitutional, moved to Sol and surrounded the tents at the weekend’s peak of hostility. Protesters shouted “Ceuta no se vende” and “Cara al sol”, and according to an on-site protester, there were “aggressions y provocaciones”. Police stepped in and detained some of those involved. After two hours of confrontation led by competing chants, National Police disbanded the demonstrators, who also directed insults at journalists and camera crews. Tensions continued through the afternoon in nearby streets. Protesters ran towards one another, bottles were thrown, and shortly before 6pm on El Carmen street, police detained a young woman after several chases. Around 7.30pm, police reinforced their presence and moved ahead with positions to stop people accessing Sol, pushing crowds back towards Plaza de Callao. Sources for Metro security said all entrances to the Metro and Cercanías at Puerta del Sol were temporarily closed at police request, then reopened later in the evening. The clashes played out while the camping organizers said they feared attacks and asked for help via social media. The standoff then shifted to the distance, with both groups continuing chants as police separated them. The latest confirmed status is that at least two people are detained following the arrests made during the incident, while police maintained control of the situation around Sol.