On Wednesday, as tropical storm Khanun made landfall off the southern coast of Japan and headed toward South Korea, airlines cancelled hundreds of flights and the government issued alerts.

Tens of thousands of campers at the World Scout Jamboree in South Korea have already started to be evacuated as a result of the storm, which has been downgraded from a typhoon. The event was already affected by a heatwave.

On Wednesday, approximately 16,000 homes were left without electricity as torrential rain lashed Kyushu, an island in southern Japan.

The Kagoshima section of the island was expected to experience torrential rain and a "surging" risk of "life-threatening mudslides and flooding," according to the Japan Meteorological Agency.

The system has been classified as a tropical storm by the Joint Typhoon Warning Center of the US military, with wind gusts of up to 81 mph (130 kph).

A spokesman for Japan Airlines told AFP that the airline on Wednesday cancelled 252 flights, affecting almost 25,000 customers. Over 10,000 people were affected by All Nippon Airways canceling 96 flights.

Events celebrating the 78th anniversary of the atomic bombing of Nagasaki were forced to be scaled back and moved inside on Wednesday because of the weather system that killed at least two people in the Okinawa region last week.

According to a statement from Kyushu Railway, several additional regional commuter and express trains were canceled, and a portion of Japan's "shinkansen" bullet train service was also suspended.

Nearly 80 flights at 10 airports, along with dozens of ferry services, were canceled in South Korea, where Khanun was predicted to make landfall Thursday.

The storm is anticipated to have "a direct impact on the whole country" from Wednesday through Friday, according to the interior ministry, prompting Seoul to boost its crisis alert level to its highest level.

According to the Yonhap news agency, the presidential administration was maintaining a round-the-clock emergency typhoon watch.

"We will do our best to respond to the typhoon, so that no human casualties occur, with thorough control and pre-emptive evacuation for the high-risk areas such as underground tunnels and riverbanks," Interior Minister Lee Sang-min said Tuesday.

The Japanese Meteorological Agency predicted that another typhoon, Lan, which was developing in the Pacific and with wind gusts of up to 108 kph, would move northwest and eventually approach the main island of Honshu in the coming days.