Intelligence authorities from Japan, the US and the EU are conducting a joint exercise to better prepare measures against cyberattacks.

The drill comes amid mounting tension in the Indo-Pacific region. Issues related to Taiwan and North Korea's nuclear and missile development are in the spotlight.

The exercise was held behind closed doors. More than 40 officials from 13 countries and regions in the Indo-Pacific region took part mainly online, including India and Taiwan and members of the Association of Southeast Asian Nations.

Government and electric power company officials also participated.

The drill simulated a computer system used at power plants and other key infrastructure facilities. It was staged on the assumption that the facility had come under a cyberattack.

The drill participants are put in charge of equipment control systems. Unauthorized access would enable the hacker to operate part of the external control system and lower the water levels of the tanks in the facility.

They learned that hackers use highly sophisticated techniques. The attackers were shown accessing software that detects abnormalities and making it display normal water level readings.

The participants also studied practical measures to deal with attacks. These included detecting unauthorized access and recovery procedures.

The countries involved in the exercise say they will continue to cooperate across borders and exchange information to counter cyberattacks in the Indo-Pacific region.

A recent survey by private research firm Teikoku Databank shows that 24.2 percent of Japanese businesses experienced cyberattacks in the past year.

More than 1,200 companies in Japan were asked to participate in the survey, which ran from October 7 through 12.

8.6 percent said they had been attacked within the past month.