Japanese weather officials have issued a heavy rain emergency warning for parts of Miyazaki Prefecture, southwestern Japan, as typhoon Nanmadol approaches.

Officials have issued the warning in Miyazaki City, Miyakonojo City, Nichinan City and Mimata Town. It is the highest level of alert and advises people to take maximum caution.

The region is experiencing its heaviest rainfall in decades.

Japan's Meteorological Agency is calling on people to check their surroundings and do whatever necessary to protect their lives.

People are advised to move to sturdy buildings nearby. If it is dangerous to go outside, they should move to the second floor or higher. Those in rooms facing a cliff or slope should move to the other side of the building.

Weather officials previously issued an emergency warning for violent winds, high waves and storm surges in Kagoshima Prefecture on Saturday evening.

Areas affected by the exceptionally powerful typhoon could suffer large-scale damage not seen in decades. Officials urge residents to maintain alert.