Italian police have arrested as many as 20 members of the Nigerian Black Axe gang in a series of raids, it was reported on Saturday (19 November). The gang members stand accused of a number of crimes ranging from protection rackets to human trafficking.

The operation comes as part of a co-ordinated effort by Italian authorities to control organised crime in the country, and was organised by a crack team in Sicily's capital of Palermo. The arrests were apparently enabled by an informer spoke to Italian police of the identities of senior members.

The gang derive their name because they are banned by "superior" Mafiosi from carrying guns and therefore use axes and machetes to deal with grievances, predominantly deal drugs imported by Italian mafia. The gang, originally from Nigeria, has been linked to high levels of migration into Italy from North Africa who are then thought to have forged links with Italy's Costa Nostra – the Sicilian Mafia.

According to reports, somewhere between 17 and 20 members of the gang are thought to have been arrested. The arrests follow earlier raids in Torino and Milan.

The Black Axe gang are said to be a splinter group of Nigeria's Neo-Black Movement of Africa. The group apparently originates from a student fraternity from the University of Benin City. The emergence of Nigerian gangs was highlighted in a letter sent to Italian prosecutors by the Nigerian ambassador to Rome in 2011. In the letter, he wrote: "I would like to draw your attention to the new criminal activity of a group of Nigerians belonging to secret societies.

"Unfortunately, former members of these sects were able to get into Italy where they re-established their criminal organisations."

Earlier this year, Palermo's deputy chief prosecutor confirmed to the Guardian that the presence of North African migrants in Italy was changing organised crime considerably. "The neighbourhoods under mafia control have changed profoundly in recent years due to the growing presence of foreigners, especially Nigerians coming on boats.

"Among them there [are a small number] of people who want to transfer their illegal trafficking, linking to prostitution and drug dealing to Sicily. And the mafia was quite happy to integrate them into their criminal business."

Migrants Italy
Migrants disembark from a merchant ship as they arrive in the Sicilian harbour of PalermoReuters