Storm is expected to bring strong winds and heavy rain as it makes it way towards South Korea and Japan’s Kyushu island.

Typhoon Prapiroon is continuing to strengthen as it heads north towards South Korea and the Japanese island of Kyushu.

Four people were injured by the storm when it battered southern Japan’s tiny Okinawa islands, according to Kyodo News.

Prapiroon is now over the East China Sea, moving northwards at 20 kilometres per hour.

The typhoon has sustained winds of 130kph, with gusts up to 170kph – the equivalent of a Category 1 hurricane on the five-point Saffir-Simpson scale used to rate the strength of storms in the waters around the Americas.

While Prapiroon is strengthening for now, it is expected to weaken as it approaches the tip of Kyushu. Cooler seas in this region, coupled with stronger winds that are blowing high up in the atmosphere, will both work together to weaken the system.

Despite its anticipated easing and the fact that the winds are tightly packed around its small centre (the eye of the storm is only 14 kilometres across) the winds could still be very hazardous.

At greatest risk of wind damage is the island of Tsushima in the Korea Strait, between South Korea and one of Japan’s main islands of Kyushu.

Japan and South Korea are aboth bracing for flooding as the storm skirts their regions on Tuesday.

Some locations are expecting as much as 300 millimetres of wet weather. This is especially of concern to South Korea, given that the country has already been swamped by torrential rain over the past few days.

More heavy rain, brought by Prapiroon, could trigger life-threatening flash flooding.