Tropical Storm Mawar unleashed torrential rain in parts of Japan on Friday prompting authorities to issue evacuation advisories for over a million people.

The storm brought gusts of up to 90 kph (56 mph) to Okinawa, resulting in eight injuries.

The Fire and Disaster Management Agency advised nearly 1.3 million individuals across Japan to evacuate in the face of the approaching storm.

More than 300 flights and 52 ferries were canceled, and a few train lines were temporarily shut down.

Earlier in the week Super Typhoon Mawar battered Guam but weakened to tropical storm status as it approached Japan's main southern islands.

Flood, landslide warnings issued

The Japan Meteorological Agency (JMA) issued flood and landslide warnings for the western parts of Shikoku and Honshu islands, with forecasts indicating up to 350mm (13.8 inches) of rainfall in certain areas of western Honshu within a 24-hour period.

Parts of Shikoku experienced intense rainfall, with 162.5mm (6.4 inches) recorded in just three hours.

Tropical Storm Mawar's impact was intensified by the warm and humid air it brought, which could possibly exacerbate the seasonal rains and heighten the risk of flooding and mudslides.

Memories of past storms

Japan has faced similar weather conditions in the past, leading to devastating flooding and landslides, such as in the summer of 2018, which claimed the lives of over 200 people.

"What happened five years ago is still as clear as yesterday," a woman in the island of Shikoku told a local media channel.

This severe weather event occurred after Japan had already experienced its warmest spring on record, the Japan Meteorological Agency said on Thursday.