Hong Kong raises highest warning for Severe Typhoon Hato

The weather observatory raised the storm warning to the city's maximum Typhoon 10 signal -- meaning hurricane force winds are expected -- at 9:10 am (0110 GMT).

It was the first such alert in five years and only the the third time the Typhoon 10 warning has been issued since 1997 when the former British colony was handed over to China.

The observatory also warned of possible flooding and said that sea levels could rise by one metre as the typhoon brought wind gusts of up to 168 kilometres (104 miles) per hour. 

The typhoon is expected to edge towards the Pearl River Estuary and to make landfall within around 100 kilometres to the west of Hong Kong in the afternoon.

Strong waves crashed into Hong Kong's coastline, with ferry services suspended, while the city's usually crowded streets were deserted and strewn with fallen branches.

The territory's flagship carrier Cathay Pacific said almost all its flights leaving before 5:00pm (0900 GMT) Wednesday would be cancelled, with Hong Kong Airlines following suit. 

Hong Kong Airport Authorities said that by daybreak, 420 flights had already been cancelled.

The city's airport express train line was also suspended while the metro rail and buses operated on a limited service.

Hong Kong is regularly hit by typhoons between July and October but direct hits are rare. 

The city saw its strongest storm in 1962 when the eye of typhoon Wanda passed over and gusts of 284 kilometres per hour were recorded.

It killed 130 people and destroyed thousands of residential huts, leaving 72,000 people homeless.

Since then, Hong Kong has adapted to typhoons, including making sure its highest commercial skyscrapers can sway in the wind, and due to the extensive lockdown procedures they now rarely cause deaths.