ONG KONG, Sept 16 - Hong Kong was shuttered Tuesday as a powerful typhoon swept past the city, bringing strong winds and rain that caused flight disruptions and forced the closure of the stock market and container ports.

Typhoon Kalmaegi, packing gusts of 125 kilometres (77 miles) per hour, was centred 400 kilometres southwest of Hong Kong as it barrelled towards the northern tip of China's Hainan island.

"Although the tropical cyclone is moving away from Hong Kong, gales are expected to persist for some time," the Hong Kong Observatory said on its website.

The Observatory hoisted the number-eight tropical cyclone warning on Monday evening and said it would remain in place until late morning Tuesday, triggering the closure of schools and businesses in the city.

At Hong Kong's airport, over 500 flights were delayed while nearly 40 were cancelled, a government statement said.

It said that there were 44 reports of fallen trees and that some parts of the city were flooded, but there were no reports of landslides.

The Hong Kong stock exchange cancelled its morning trading session and said it would remain closed for the day if the number-eight warning -- the third in a five-tier warning system -- was still in force by noon.

Typhoon Kalmaegi swept out of the Philippines on Monday after causing chest-deep floods in some rural areas but leaving the storm-prone country largely unscathed.

Six people were killed after a passenger ferry sank in the central Philippines on Saturday amid rough weather as the storm approached, the navy said.

Hong Kong was buffeted by two typhoons last year.

In August 2013 helicopter teams saved all 21 crew from a cargo ship that sank as Severe Typhoon Utor passed within 240 kilometres of the city, generating waves of up to 15 metres (50 feet).

And in September Typhoon Usagi -- the year's most powerful storm -- caused transport chaos in the city before crashing ashore in southern China.