Japanese mobile phone carrier KDDI says it is experiencing a major disruption to its phone and data communication services across the country.

The company says the problem started around 1:35 a.m. on Saturday.

KDDI mobile services include au, and its brands, UQ mobile and povo.

The company has issued an apology to users for the inconvenience. It says it does not know when services will resume.

Another mobile carrier Rakuten Mobile says its customers are also experiencing connection issues in some areas where the company uses KDDI networks.

The Meteorological Agency says the problem has affected the distribution of some weather data. But it says typhoon forecasts have not been disrupted so far.