TOKYO, Aug 28 (Reuters) - Japan issued an emergency warning on Wednesday as powerful Typhoon Shanshan approached the southwestern region with heavy rain and strong winds, prompting Toyota Motor to suspend operations at all of its domestic factories.

Airlines and rail operators also cancelled some services over the coming days as the typhoon, categorised as "very strong", packed winds of 50 metres per second with gusts of up to 70 metres per second (252 km per hour/157 mph).

"Maximum caution is required given that forecasts are for strong winds, high waves and high tides that have not been seen thus far," the Japan Meteorological Agency warned.

Shanshan is expected to strike Japan's southwestern Kyushu island over the next few days and approach the central and eastern regions, which includes the capital Tokyo, around the weekend, JMA said.

Authorities issued evacuation orders for more than 800,000 residents in Kagoshima prefecture in Kyushu and the central Aichi and Shizuoka prefectures.

In Aichi, home to Toyota's headquarters, two people believed to be residents of a house that collapsed in a landslide during heavy rains were unaccounted for. Three residents of the house had been pulled out, according to public broadcaster NHK.

Toyota will suspend operations of all 14 plants in Japan from Wednesday evening through Thursday morning, it said.

Typhoon Shanshan is the latest harsh weather to hit Japan following last week's Typhoon Ampil, which also led to blackouts and evacuations.

ANA Holdings said it would cancel more than 210 domestic flights in total between Wednesday and Friday slated to leave or arrive in southwestern Japan, affecting about 18,400 passengers.

Japan Airlines said it would cancel 170 domestic flights through Thursday. A total of 10 international flights operated by both airlines will also be suspended.