Super typhoon Mangkhut, with hurricane-force winds well over 200 km/hr, barrelled past the northern tip of the Philippines, killing at least 50 people.

It then skirted south of Hong Kong and the neighbouring gambling hub of Macau, before making landfall in China.

Parts of Hong Kong and Macau were severely flooded, though there were no immediate reports of any fatalities. Two people were reported killed in Guangdong, China's most populous province and home to over 100 million residents, state media reported.

The China Meteorological Administration said the typhoon, dubbed "King of Storms", swept west to Guangxi province early on Monday morning and weakened to a "tropical storm". It forecast the storm to hit the regions of Guizhou, Chongqing and Yunnan later on Monday.

The meteorological administration says Mangkhut is one of the 10 biggest storms to hit southeast China since 1949 - when records began - with wind speeds at around 162 km/hr.

Across Hong Kong, authorities strived to clear roads of debris, including toppled trees and bamboo scaffolding. Some buildings, including the One Harbourfront office tower, had many windows smashed after a day in which some of the city's skyscrapers had swayed with the ferocious gusts.

Stock and financial markets opened as normal on Monday in Hong Kong and the southern Chinese city of Shenzhen.

Some transport services remained suspended, though flights in the region were slowly resuming after a shutdown on Sunday, stranding many thousands of passengers.

In Macau, badly hit by a super typhoon last year, authorities were much more prepared this time, ordering casinos to close late on Saturday night as the storm approached.

Casinos were operational again early on Monday though authorities were still struggling to restore power to some of the 20,000 households that suffered power cuts.

Australian Associated Press