FILE PHOTO: A member of the Hells Angels attends the funeral of Aygun Mucuk, shot president of the Giessen chapter of the Hells Angels in Giessen, Germany, October 12, 2016. REUTERS/Kai Pfaffenbach/File Photo

LISBON (Reuters) - Over 400 Portuguese police, including the antiterrorism unit, detained several dozen members of the Hells Angels motorcycle club in raids on 80 homes and localities across the country on Wednesday.

Police said the operation followed investigations into the international group’s activities in Portugal, adding that some of its members were “extremely dangerous”, with long criminal records and long experience of organized violent crime.

The raids took place about a week before an annual international motorcycle gathering in Faro in southern Portugal, which brings together thousands of bikers from all over Europe.

One of the investigations has been looking into an attack in March by a group of Hells Angels members, some of them foreign, against a rival motorcycle gang and their allies from a neo-Nazi group in what the authorities believe is a turf war for control of illicit guns and drug trade.

Several people were injured in the attack which occurred in a restaurant near Lisbon.

Hells Angels MC, born in the United States after the Second World War and active around the world, opened their Portugal charter in 2002. Nobody was available for comment at the club’s only listed Portuguese contact number in Porto.