Tokyo, Aug 11 : Japan's weather agency issued a heavy rain emergency warning for the southwestern prefecture of Kumamoto on Monday morning, calling for maximum caution as the risk of disasters could rise quickly.

The Japan Meteorological Agency (JMA) added Amakusa City to the country's highest level heavy rain warning list at 9:15 a.m. local time. Warnings are already in effect for the cities of Tamana, Uki, Yatsushiro and Kami-Amakusa, and the towns of Nagasu and Hikawa in the prefecture.

Weather officials urged people in areas covered by the warning to immediately secure their safety, adding that people in landslide warning areas should exercise utmost caution.

At least four people have been reported missing as heavy rain continues to pound the southwestern Kyushu region, causing landslides and widespread flooding, reports Xinhua news agency, quoting public broadcaster NHK.

In Kumamoto Prefecture, someone had been swept away early Monday in a river in Tamana City, and one man is unaccounted for after a landslide in Kosa Town.

Meanwhile, authorities in Fukutsu City, Fukuoka Prefecture, said a man and a woman in their 60s were swept away in a river and are missing, the report said.

Weather officials warned people to remain on alert as dangerous conditions may already exist in affected areas.

Meanwhile, heavy rainfall continues to lash the city of Kirishima in the southwestern prefecture of Kagoshima.

A part of Kirishima registered 107.5 mm of rain in the hour to 3 a.m. local time on Friday, the heaviest on record at the location. The 12-hour total reached over 480 mm, about 1.8 times the city's August average.

/IANS