One of the largest bitcoin exchanges on the Internet has temporarily suspended its services after losing some 19,000 bitcoins ($5.1 million) in what the company said was a breach of its systems.

In a message on its site dated January 6, Bitstamp said some of its operational wallets were compromised on January 4. The company said that upon learning of the breach it advised all of its customers to no longer make deposits to previously issued bitcoin deposit addresses.