CHANGSHA - A plan to build the world's tallest building in Central China's Hunan province has not yet been approved, a local official said in response to reports that the project has broken ground.

The "Sky City" project in Changsha, capital of Hunan, still has to go through procedures before construction can start, an unnamed official at Hunan's housing and urban-rural development department told Xinhua.

Media reports said construction on the skyscraper began on July 20 with a ceremony attended by Zhang Yue, president of Broad Group, which is in charge of the building.

At 838 meters, the tower would be taller than the Burj Khalifa in Dubai, the world's current tallest building, by 10 meters. It is planned to house schools, hospitals, offices, apartments and even an 8,000-square-meter garden, according to Broad Group plans.

The company said construction is expected to be completed in April 2014, triggering discussions on the speed of construction of the building and its safety.

Broad Group declined to comment on the issue.

A report issued last year said the Chinese mainland will outstrip the United States to have the most skyscrapers during the next decade.