The potentially record-breaking winds stemmed mainly from a "cold vortex system" that formed over Mongolia and was sweeping across northern China from Friday through the weekend, the China Meteorological Administration (CMA) said.

"The strongest winds are expected during the daytime of April 12, with wind speeds at some observation stations approaching or even surpassing historical records for the same period since 1951," the CMA said in a statement.

It warned residents in those areas not to go outdoors "unless necessary".

Beijing earlier issued its first orange alert -- the second-highest tier -- in a decade warning of strong winds this weekend.

As many as 699 flights had been cancelled at Beijing's two airports by Saturday afternoon, state broadcaster CCTV said.

Train services, including on multiple high-speed rail lines, have also been suspended, it said.

Tourist attractions including the Summer Palace, Temple of Heaven, Beijing Zoo and the Universal Studios theme park were also closed temporarily.

Beijing authorities also postponed a half- marathon that was to have featured humanoid robot racers on Sunday.

Almost 300 trees in the capital had been toppled and 19 vehicles damaged, CCTV said, although no injuries due to the strong winds had yet been reported in Beijing.

China is the world's biggest emitter of the greenhouse gases that scientists say are driving climate change and making extreme weather more frequent and intense.

Dozens of people were killed and thousands evacuated during storms that caused severe flooding around the country last year.

A highway in southern China collapsed in May after days of rain, killing 48 people.