In Barcelona, police identified nearly 1,000 people in the city centre during Halloween-night checks. The Mossos d'Esquadra and Guardia Urbana also filed 63 administrative reports over possession of items considered capable of being used to cause disorder or attack shops. More than 500 officers were deployed around Plaça Catalunya and Passeig de Gràcia. A later tally by midnight put the number of people identified at 1,440. It recorded three arrests as a separate enforcement measure; identifications, reports and arrests were counted separately.
Officers arrested a young man linked to the call after finding him with a knife and a balaclava. He also had tools for breaking shop windows.
The operation was organised after looting and damage at several Barcelona shops on 24 October. Reporting on that night counted 23 establishments being looted. Up to 133 arrests were made, with more than half of those detained reportedly minors. Around 15 police officers were injured. The Mossos d'Esquadra described the spread of the disturbances as unprecedented, information from El Mundo. Calls to provoke disorder and vandalise businesses had circulated on social media and messaging channels, presenting the mobilisations as protests while allegedly encouraging looting and violence. The October incidents were covered in earlier reporting.
Security was reinforced in Madrid and Barcelona. Valencia also saw a stronger deployment, as did Bilbao and Palma. Many businesses protected their shopfronts and some closed early, while most cities ended the night without major incidents. Across Spain, the operation reportedly resulted in more than 2,200 identifications and 11 arrests. The announced gathering in Palma's Plaza de España drew no participants; mobilisations in Bilbao ended without incidents.
In Valencia, local police identified 105 people during the afternoon and seized a plastic pistol along with two balaclavas. Officers also filed several reports involving drugs or pyrotechnics. They took four masks and kept the operation in place through the night. At Espai Gironès shopping centre in Salt (Girona), police presence allowed shops and restaurants to operate normally.
Police also made arrests over the circulation and organisation of the calls. A 21-year-old in Barcelona province was identified as an administrator of a group used to coordinate violent actions. Mossos d'Esquadra arrested him in Cabrera d'Anoia on 31 October over his alleged links to Blocus channels and the 24 October vandalism. A separate 17-year-old detained in Sant Sadurní d'Anoia was reportedly placed in a closed juvenile facility. In Valencia, a minor was arrested for distributing messages intended to bring people into other chats linked to the movement.
The alleged founder of Blocus España was detained in Picanya (Valencia) on 30 October. The Spanish Ministry of the Interior described the 20-year-old as the alleged founder and principal promoter of the movement, which it linked to social-media calls that allegedly used the appearance of student protests to encourage looting and violence. On 31 October, a Torrent court ordered provisional detention without bail. The measure allowed communication but restricted access to computers and other devices capable of providing access to social networks. The detention is a pre-trial measure, not a final finding of guilt. Another person arrested in connection with the movement also entered prison by judicial order.
