The Hong Kong Special Administrative Region government on Monday reminded Hong Kong residents traveling to Japan to exercise caution following Tokyo’s unprecedented warning that the risk of a major Pacific coast earthquake was higher than usual.

An HKSAR government spokesman noted that Japanese authorities issued a megaquake advisory for parts of Japan after a magnitude 7.1 earthquake hit Miyazaki prefecture on Aug 8.   

"Given it is now the peak travel season during the summer holiday and that Japan is a popular travel destination for Hong Kong residents...the government reminds Hong Kong residents who intend to visit the country or are already there to exercise caution, attend to personal safety and monitor the announcements by the Japanese authorities," the spokesman said in a statement.

ALSO READ: What is Japan's Nankai Trough megaquake advisory?

The Japan Meteorological Agency issued on Thursday its first-ever advisory on higher-than-usual risks of a megaquake, that could be as powerful as magnitude 9.1, along a tremulous seabed zone along the Pacific coast known as the Nankai Trough.

A possible Nankai Trough megaquake and tsunami disaster could kill hundreds of thousands of people and cause a trillion-dollar damage to Japan.

Coupled with landslides and fire, such a disaster would be expected to claim the lives of as many as 323,000 people and destroy 2.38 million buildings, forcing nearly 10 million survivors to evacuate.

Japanese Prime Minister Fumio Kishida canceled plans to visit central Asia on Friday after the megaquake advisory was issued.

READ MORE: Japan's PM cancels central Asia trip after earthquake risk warning

The HKSAR government spokesman said Hong Kong residents in Japan who need assistance may call the 24-hour hotline of the Assistance to Hong Kong Residents Unit of the Immigration Department at (852) 1868, or use the 1868 Chatbot via the Immigration Department Mobile Application.

They could also send a message to the 1868 WhatsApp assistance hotline or the 1868 WeChat assistance hotline or submit the Online Assistance Request Form or contact the Chinese Embassy in Japan at the consular protection hotline: +81-3-6450-2195.

Hong Kong residents are also encouraged to use the online Registration of Outbound Travel Information service of the ImmD to register their contact details and itinerary when outside Hong Kong.

With inputs from Agencies