TOKYO, July 4 (Xinhua) -- Japan's telecom giant KDDI Corp. said Monday that services including voice calls and data communications have almost been restored nationwide, after nearly three days of maintenance work to fix a large-scale outage.
The disruption, which occurred around 1:35 a.m. Saturday local time (GMT 1735 Friday), has affected up to 39.15 million mobile phone connections and a range of business activities.
The malfunction has disrupted banking systems, the transmission of weather data, parcel deliveries, and network-connected cars.
KDDI, the country's second-largest mobile carrier by subscribers, is facing calls for compensation from customers, while the government is expected to take administrative measures to improve its businesses and prevent a recurrence.
KDDI shares dropped nearly 4 percent at one point during the day's trading.
Users of its mobile services continued to find it difficult to make calls on Monday due to a temporary limit placed on network traffic, although Internet and data communication services were largely restored earlier in the day.
KDDI said it expects to determine by Tuesday evening whether the service is completely back to normal.
KDDI President Makoto Takahashi admitted it was the largest outage in its corporate history at a press conference Sunday.
He apologized for the disruption and said that the company is considering compensating individual and corporate users.
The government considers the trouble "extremely regrettable" as mobile networks are important infrastructure for the public and its activities, Deputy Chief Cabinet Secretary Seiji Kihara said at a press conference, urging KDDI to offer an "in-depth explanation to users." ■