A man works to remove roofs blown off into a street by Typhoon Haishen in Fukuoka, Japan on Monday. Photo: AFP

Powerful Typhoon Haishen approached South Korea on Monday after slamming southern Japan with record winds and heavy rains that prompted evacuation warnings for millions.

On Monday morning, initial assessments suggested the storm had done less damage than feared, though hundreds of thousands of homes were left without power across much of Japan's southern Kyushu island.

At 7 am, the typhoon was 30 kilometers north of Tsushima Island and was categorized as a "large" and "strong" storm, having weakened overnight, but was still packing gusts up to 216 kilometers per hour.

Several dozen mostly minor injuries were reported, according to national broadcaster NHK, most of them elderly people who suffered falls.

In Nagasaki's Goto, four people were hurt after a shattered window flung glass into an evacuation center in the early hours of Monday morning, a local fire department official told AFP.

"It was unclear if the window was smashed in by a gust of wind or something that blew into it," he said.

Weather officials had warned the storm's strongest gusts would be strong enough to overturn cars and snap powerline poles.

By Monday morning, around 476,000 households were without electricity, according to Kyushu Electric Power, raising fears of heatstroke for those left without air conditioning.

Authorities issued non-compulsory evacuation orders and lower-level advisories for more than 7 million people at the peak of the storm.

But they also asked residents to avoid crowding at shelters to reduce the risk of the coronavirus infections.

Some shelters were forced to turn people away to have enough space to maintain social distancing, and many of those advised to evacuate decided to check into hotels.

Hotel Polaris in Shibushi, Kagoshima, said all 73 of its rooms were booked out for the weekend - the first time it had been fully booked during a typhoon.

"This is a large building for our area. I think our guests have chosen to stay with us to feel safe," front desk employee Takayuki Shinmura told AFP.

AFP