Hundreds of flights have been cancelled across Hong Kong and the neighbouring Chinese province of Guangdong ahead of the arrival of Super Typhoon Saola.
Schools and businesses were also closed ahead of the arrival of the storm which is now moving over Hong Kong.
The Hong Kong Observatory – a government department responsible for issuing warnings on weather-related hazards – said at 8.15pm local time (1.15pm UK): “The eyewall of Super Typhoon Saola is now moving across Hong Kong, posing a high threat to Hong Kong.
“Hurricane force winds are affecting the eastern part of Hong Kong.”
It has issued a ‘Typhoon 10’ hurricane signal, meaning that winds with mean speeds of 73mph or more are expected. Wind speeds could reach up to 125mph.
Public offices are shut down when the ‘Typhoon 8’ signal is issued.
“The Hurricane Signal, No. 10 is expected to remain in force for some time,” said the observatory.
“Members of the public should stay on high alert. You are advised to remain where you are if protected and be prepared for destructive winds.”
It warns that water levels in low-lying coastal areas will rise rapidly overnight and may reach a historical record.
“There will be serious flooding, the flood depth in some areas may be more than one metre,” said the observatory.
The UK FCDO said in its updated advisory for Hong Kong: “Flights have been affected so check with your airline ahead of travel and be prepared to change your plans.
“Other transportation services in Hong Kong have been suspended.
“Travellers are advised to remain indoors until the storm warning signal has reduced.”
Travellers are urged to visit the FCDO tropical cyclones page for advice about how to prepare if affected by a hurricane or tropical cyclone.
It notes that the typhoon season in Hong Kong normally runs from April to October and the storms may cause flooding and landslides.