By Quentin Somerville
BBC News, Shanghai
Growing number of ultra-high skyscrapers in China could be at risk from earthquakes, according to a government ministry.
New skyscrapers are being built all over China
Deputy construction minister Huang Wei says many of the buildings use designs untested in earthquakes.
But the architects say their buildings are safe, and undergo rigorous testing to withstand earthquakes and typhoons.
Land is at a premium in China, so despite its concerns the government is unlikely to impose limits.
Higher and higher
A number of Chinese cities are racing to build the mainland's tallest skyscraper.
On the once muddy banks of Pudong in Shanghai, China's tallest building is under construction.
The World Financial Centre will eventually rise to 492m (1614 feet), making it one of the tallest buildings in the world.
In Guangdong they plan to go even higher with a TV tower that will rise to 600m (1970 feet).
Inter-regional rivalry is spurring this race upwards, and is worrying the country's construction ministry.
Huang Wei says foreign architects, who are designing many of China's new showpiece buildings, lack the experience to build in an earthquake zone.
Earthquakes are common in China. One of the worst quakes in the last century took place in Tangshan in the north of the country, killing almost 250,000 people.