Typhoon Jangmi on Wednesday ripped through the Pacific side of western and eastern Japan after making landfall in the morning, causing flooding and mudslides and leaving dozens of people injured.

The typhoon made landfall around 4.30am in the southern part of Wakayama Prefecture in western Japan, after it passed near Okinawa and Kagoshima prefectures the past two days.

At one point, the weather agency issued its highest level 5 flood warning for the Koza River in Wakayama Prefecture, meaning the situation was life-threatening and people needed to ensure their safety immediately.

The Fire and Disaster Management Agency said 23 injuries were reported in six prefectures, including Aichi and Nara, with 17 having occurred in Okinawa as of 2pm on Wednesday.

Even though Koza River began overflowing its banks, the level 5 emergency flooding warning for the river was downgraded at 8.50am, according to the Japan Meteorological Agency.

In Shizuoka Prefecture, a landslide occurred around 11am, sending mud onto a railway line, but no one was injured as services had already been suspended for the day, according to local police and the railway operator.

Chief Cabinet Secretary Minoru Kihara said the government had received reports of flooded roads, toppled trees and landslides from Kyushu to the Kanto region, which includes Tokyo, as the typhoon brought heavy rain over a wide area.