They are accused of stealing more than 40m credit and debit card numbers before selling the information.

They allegedly hacked into shop and bank computer systems using a technique known as "wardriving" and installed software to access the data.

Prosecutors said the alleged fraud was an "international conspiracy".

'Increasing vulnerability'

Three of those charged are US citizens. The others come from Estonia, Ukraine, Belarus and China.

The 11 suspects are alleged to have illegally obtained card numbers, account information and password details by driving around neighbourhoods and hacking into wireless equipment.

They are said to have then concealed the information in computer servers both in the US and Europe.