According to lawyers Martins Leitão and José Carlos Cardoso, the defendants must present themselves once a month to authorities and are prohibited from contacting each other and other members linked to the Hells Angels.

They are also prohibited from participating in biker gatherings, being in spaces usually attended by bikers and leaving the country.

This case already has 87 defendants.

The police arrested these 17 members on Tuesday based on suspected criminal association and other crimes.

On that day, the police said that the men were aged between 29 and 52 and that the operation carried out is part of the same investigation into which 41 defendants are in pre-trial detention since July 2018.

In March last year, about 20 bikers of the Hells Angels group invaded a restaurant in Prior Velho, near Lisbon, to attack the Red&Gold group, created by rival Mário Machado. The two groups got into a fight inside the establishment, with knives, sticks, iron bars and other objects.

This episode of violence led the police to begin a nationwide operation and to hold, in July last year, the first 58 members of the motorcycle group Hells Angels in Portugal (which had one in Germany).

The suspects are indicted of criminal association, attempted first-degree homicide, theft, assault, possession of prohibited weapons and drug trafficking.

There have been Hells Angels groups in Portugal since at least 2002. In the US, where the organisation was founded in the 1940s with its members typically ride Harley-Davidson motorcycles, it has for several years been considered by the Department of Justice to be an organised crime syndicate.