TOKYO, July 7 (Xinhua) -- Death toll has risen to 21 while at least 47 people are still missing as wide swathes of Japan were pummeled by torrential rain since Thursday, local media reported Saturday.

Record levels of rainfall have continued to hit wide swathes of Japan with evacuation orders or advisories being issued for more than 3 million households across 20 prefectures.

Some 48,000 members of Japan's Self-Defense Forces, police and firefighters are searching for the people trapped or wounded in landslides and flooding triggered by the heavy rain, according to the government.

The Japanese government has set up a liaison unit at the crisis management center of the prime minister's office to gather information.

According to the Japan Meteorological Agency (JMA), an active seasonal rain front is causing torrential rain in most eastern and western regions of Japan, which could continue until Sunday.

The agency said that atmospheric conditions from western to northern Japan are set to remain very unstable owing to warm and moist air flowing into a low pressure system and an active front close to northern Japan.

The agency warned that Japan's Kinki region, which includes Kyoto, Hyogo and Osaka prefectures, could be particularly hard-hit by downpours, escalating the risk of floods, landslides, lightning and tornadoes.

Rivers from Hokkaido to Kyushu have been reported as running at above flood warning levels and the weather agency has warned of further landslides.

The JMA urged people to stay vigilant and listen out for emergency alarms from local governments issuing advisories or calling for immediate evacuations.