Heavy rain pounded islands in southwest Japan as a typhoon headed toward the Korean Peninsula on Saturday, leading the Meteorological Agency to issue the highest-level danger alert for parts of Nagasaki Prefecture.

Landslides occurred on Tsushima Island and the Goto Islands in Nagasaki. Two women were injured in a town in the Goto Islands after they fell off a roof while repairing leaks, according to local authorities.

"We call for people to show the highest level of caution even in areas where people may not expect a disaster," a Meteorological Agency official said, noting the torrential rain accompanying Typhoon Danas may continue into the evening.

In the cities of Tsushima and Goto, about 110 mm of rain was recorded falling over an hour-long period in the morning.

All 30,000 residents of Tsushima were subject to evacuation advisories and the 36,000 residents of Goto were given evacuation orders.

Prime Minister Shinzo Abe ordered related ministries to provide information promptly and support evacuation.

In the 24 hours through Sunday noon, up to 200 mm of rain is expected in northern Kyushu, 150 mm in southern Kyushu and Shikoku, and 100 mm in the Chugoku region.

The typhoon is expected to make landfall on the Korean Peninsula on Sunday and is likely to be downgraded to an extratropical cyclone later in the day.