Mizuho Bank experienced a system failure which disrupted about 100 automated teller machines on Wednesday, the Japanese major banking group said, marking the seventh such outage this year.

The failure occurred around 9:20 a.m. due to a "hardware problem," but affected services have been restored, Mizuho Bank said.

The last system problem on Aug. 23 disrupted around 130 ATMs, which followed a more extensive disruption on Aug. 20 affecting transactions at branch counters across Japan of Mizuho Bank, the core unit of Mizuho Financial Group Inc.

The bank also saw large-scale system failures in April 2002 and March 2011.

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