Typhoon Shanshan was 80 kilometres (50 miles) northeast of the southern Amami archipelago on Wednesday morning with gusts of up to 252 kilometres (157 miles) per hour.

A wall of mud, rocks and other debris swept away the house in Gamagori, a city in central Aichi prefecture, late on Tuesday after hours of pounding rain.

"The landslide hit a house where five family members were living -- a couple in their 70s, two women in their 40s and a man in his 30s," a Gamagori official told AFP.

"One of them were rescued late Tuesday, but the search for the four others have been continuing through the night," he said.

The weather agency may issue a special heavy rain alert for Kagoshima prefecture including Amami later Wednesday, an agency official said in a morning news conference.

"It's necessary for us to be on the highest alert," he said.

Airlines have cancelled dozens of flights while some bullet train operations may be suspended this week, depending on the course of the typhoon, operators said.

Shanshan was expected to veer towards the main southern island of Kyushu this week.

It comes in the wake of Typhoon Ampil, which disrupted hundreds of flights and trains this month.

Despite dumping heavy rain, it caused only minor injuries and damage.

Ampil came days after Tropical Storm Maria brought record rains to northern areas.

Typhoons in the region have been forming closer to coastlines, intensifying more rapidly and lasting longer over land due to climate change, according to a study released last month.