The Hague (AFP) - European and US police have arrested 17 people running online "dark" markets selling illegal products and services in a joint operation against the supposedly anonymous Tor network.

Police from the United States and 16 European countries, including France, Germany and Britain, on Thursday "undertook a joint action against dark markets running as hidden services on Tor network," European police agency Europol said in a statement.

Tor is an online encryption service that protects a computer user's unique identifying IP address, used to set up private web connections in what has become known as the Darknet -- a hidden network used for both licit and illicit activities.

"The action aimed to stop the sale, distribution and promotion of illegal and harmful items, including weapons and drugs, which were being sold on online 'dark' marketplaces," Europol said on Friday.

The operation seized virtual Bitcoins worth one million dollars (800,000 euros), 180,000 euros in cash as well as unspecified drugs.

"We are not 'just' removing these services from the open Internet," said Troels Oerting, the head of Europol's EC3 cybercrime unit.

"This time we have also hit services on the Darknet using Tor where, for a long time, criminals have considered themselves beyond reach. We can now show that they are neither invisible nor untouchable."

US authorities on Thursday said they had shut down a reincarnation of the Silk Road online black market bazaar for drugs and other illicit goods and charged its alleged 26-year-old operator.

US prosecutors say Silk Road 2.0 enabled more than 100,000 people to buy and sell illegal drugs and other contraband anonymously over the Internet after its predecessor was shut down in 2013.