Beijing-based virtual currency exchange Vircurex has frozen customer accounts because it does not have the reserves to cover withdrawal requests.
In a statement on its site the exchange says that it has stopped all bitcoin, litecoin, terracoin and feathercoin withdrawals and is freezing accounts.
Vircurex lost "significant" amounts of these currencies in two hacks last year. Since then the firm has been using the funds in its cold wallet to keep the platform going and gradually refill the wallets of customers who lost out.
However, over the last few weeks several large withdrawals have been made "which have lead [sic] to a complete depletion of our cold wallet balance".
Vircurex says that is now freezing accounts and resetting balances to zero, but is promising to take its profit each month and gradually top up the frozen wallets.
The exchange's troubles come a month after Mt. Gox was forced to shut its doors after losing customer bitcoins worth hundreds of millions of dollars.