The Portuguese Public Security Police have made 12 arrests during raids on FC Porto ultras.

The raids, dubbed ‘Operação Pretoriano’ came in response to violent attacks at Porto’s General Assembly meeting on November 13.

Security forces told CNN Portugal that they seized: “Several thousand euros, three motor vehicles, a firearm, more than a hundred tickets to sporting events, pyrotechnic artefacts, various narcotics (namely cocaine and hashish) as well as electronic equipment and other documents of interest to the investigation in question.”

The 12 arrests – of which 11 were men and one woman – were made ‘in the context of combating the crimes of qualified physical integrity offences, aggravated coercion, aggravated threat, public instigation to commit a crime and attack on freedom of information’.

The arrests included leader of the Super Dragões, Fernando Madureira, and other prominent ultras – Vítor Catão and Fernando Saul.

The detainees will be brought before a judge on Thursday for sentencing.

Long queues, lack of organization and scenes of violence marked the Extraordinary General Assembly of FC Porto on November 13th.

The meeting was scheduled for 9pm, but thousands of fans, including André Villas-Boas, former Porto coach and candidate to become the club’s president, were moved from the auditorium at the stadium to the Dragão Arena, which led to a 45-minute interruption.

Afterwards, scenes of violence were seen inside Dragão Arena and members were faced with what media outlets described as ‘an atmosphere of intimidation’.

Many left, but the AG was only suspended when a member was attacked and removed from the premises after speaking. In the end, the main meeting was cancelled and postponed until November 20th.