Just a week after one of bitcoin's major exchanges, Mt.Gox, went offline—and then filed for bankruptcy—a bitcoin bank was forced to close after hackers stole 896 bitcoins, worth over $600,000.

The bitcoin bank Flexcoin posted a note on its site stating: "On March 2, 2014 Flexcoin was attacked and robbed of all coins in the hot wallet. ... As Flexcoin does not have the resources, assets, or otherwise to come back from this loss, we are closing our doors immediately."



The term "hot wallet" refers to bitcoins stored in an online wallet connected to the Internet.

(Read more: Bitcoin believers unfazed by losses in Mt.Gox fall)



Last week, Mt.Gox blamed hackers for stealing an estimated $480 million worth of bitcoins, due to what it called a weakness in its system. The company opted for bankruptcy protection in Japan on Friday.



Despite detailing outstanding debts of about 6.5 billion Japanese yen ($63.6 million), 850,000 lost bitcoins and 127,000 empty-handed customers, the exchange said it was looking to continue doing business.



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