A firefighter inspects a flooded parking lot in Gurye County, South Jeolla Province, in this photo provided by Gurye Fire Station, Sept. 20. Yonhap

The Ministry of the Interior and Safety said Friday the government raised the heavy rain warning level by one notch from "interest" to "caution," as a torrential rain advisory has been issued for the nation's central and southern regions, and the southern island of Jeju.

The ministry also activated "Level One" of the Central Disaster and Safety Countermeasures Headquarters' emergency response posture and asked all relevant government offices to implement safety measures against landslides, flooding of underground passages and other damage from downpours.

According to the Korea Meteorological Administration (KMA), heavy rain of more than 30 millimeters was falling per hour in the southern provinces of Jeolla, central provinces of Chungcheong and Jeju as of Friday afternoon.

The KMA forecast that many of the affected regions will receive more than 150 mm of rain by Sunday amid strong winds. The precipitation may reach up to 300 mm in mountainous areas of Gangwon Province, the agency added.

The greater Seoul area will receive 30 to 100 mm of rain until Sunday, it noted. (Yonhap)