Spain's Civil Guard has taken down a gang that employed extremely violent tactics in robbing drug dealers, arresting 15 suspects, officials said Thursday.

The suspects - eight Colombians, two Spaniards, two Brazilians, an Argentine, a Peruvian and a Briton - may have earned "big profits" by stealing from victims who were unlikely to call police, the Civil Guard said in a statement.

The gang would make contact with dealers, showing them small bits of cocaine or white substances that appeared to be the illegal drug.

When it was time to seal the deal, the suspects would assault and rob the drug dealers, the Civil Guard said.

The suspects were arrested during an operation conducted on the island of Tenerife and in the provinces of Madrid and Guadalajara.

The 15 suspects face organized crime, drug, robbery, forgery and other charges.

The gang, which was led by two Colombian brothers, operated across Spain and in other parts of Europe.

The suspects usually staged the rip-offs in parking lots and apartments, some of which were rented just for the occasion.

The gang's members, who would wear ski masks and carry starter's pistols, hid in the dwellings chosen for the robberies or in the trunks of cars.

Drug buyers would be robbed of their money by the suspects, who used "great violence" and then fled from the scene quickly, the Civil Guard said.