The Dubai Criminal Investigation Department (CID) had received information in July this year that a gang of Arab men were stealing credit card information from people making online transactions on websites that offer government and semi-government services, and purchasing online from some shops.
Colonel Khalil Ebrahim Al Mansouri, deputy director of the CID, said the suspects stole information from 16,975 credit cards.
Police say the information was then used by the gang to make their own transactions online for goods, including gold and diamonds.
The CID said it raided "the gang's den and arrested them red-handed with the devices they were using to carry out their operations".
Two people were arrested, and they then guided the police to a third suspect, who had already been detained at a police station for another case.
Police also identified a fourth suspect who was outside the country. Police made the necessary arrangements to extradite him. The CID did not name the country.
Earlier this year, Dubai arrested another gang for allegedly using multiple forged credit cards to buy laptops and other expensive goods.