Thirteen Japanese bitcoin exchange operators said Tuesday they will suspend deposits and withdrawals of the virtual currency from midnight July 31 (3 p.m. GMT) in order to prevent possible turmoil stemming from an expected separation of the trading system.

They aim to protect customers' assets through the trading suspension.

The number of bitcoin users is rapidly increasing partly on the back of low commissions for overseas remittances. But the growing transaction volume has helped increase speculative trading, and the exchange operators are taking longer to execute transactions as a result.

Against this background, some in the bitcoin industry are planning to set up a new system enabling faster transactions, while others are calling for the continued use of the current system.

Explaining the reason for the planned trading suspension, a virtual currency association to which the 13 exchange operators belong said that it is difficult to estimate how big the possible confusion will be and that the risk of a serious problem happening cannot be ruled out.