Typhoon Ragasa has made landfall in southern China, where nearly two million people have been evacuated in preparation for its arrival.

It comes after authorities said at least 17 people had been killed and more missing in Taiwan after a lake burst on Tuesday, causing severe flooding in the island's east.

Ragasa was downgraded from a super to a severe typhoon on Wednesday but it remains highly destructive, with top winds of 241km/h (150mph) recorded in Taishan county in China's south-eastern Guangdong province.

The equivalent of a Category 5 hurricane, Ragasa is the world's strongest storm this year and has been roaring over the South China Sea for days.

Ahead of making landfall, 90 people were injured in Hong Kong as the storm skirted its coastline, the hospital authority said.

The typhoon made landfall on the coast of Hailing Island, Yanjiang City in Guangdong at about 17:00 local time (9:00 GMT) on Wednesday, according to Chinese state media.

It crossed the mainland with sustained winds of 144km/h and higher gusts. Wind speeds are expected to gradually weaken as the storm moves westwards over land but rain will be torrential and slow-moving across the region for several more days.

The southern Chinese cities of Zhuhai, Shenzhen and Guangzhou - all located in Guangdong - were braced for seawater intrusion from about midday local time.

In Zhuhai, police patrolled the streets with sirens and megaphones, telling people to stay at home.

Red alerts for landslides were also issued in the mountainous regions of Guangdong province.

Away from the Chinese mainland, authorities in Taiwan are still dealing with the destruction caused by Ragasa, which officials have described as being far worse than anticipated.

Premier Cho Jung-Tai has demanded an inquiry into how evacuations were carried out after at least 17 people died following the burst of a barrier lake in Hualien county, causing severe flooding in the town of Guangfu.

Geologists have described the breach as a tsunami from the mountains, as an estimated 15.4 million tonnes of water were released when the dam burst.

Though the typhoon did not make landfall in Hong Kong, the hospital authority reported injuries as a result of powerful winds and heavy rain.