SHANGHAI (REUTERS) - The central Chinese city of Wuhan has banned the further deployment of shared bikes as it tries to deal with congestion and "chaos", the official Xinhua news agency reported late on Monday (Sept 4).

The number of shared bikes in Wuhan's urban districts is already approaching 700,000, far exceeding the city's "carrying capacity" of 400,000, with operators such as Ofo and Mobike expanding rapidly since launching in the city at the end of last year, Xinhua said, citing an official statement.

Shared bikes have become ubiquitous throughout China's major cities, with users now able to access an estimated 16 million vehicles nationwide through apps downloaded on their mobile phones, according to estimates from the transport ministry.

But inadequate regulation has caused mayhem on China's roads and pavements, with thousands of bikes discarded or dumped in already crowded public spaces.

Several giant cities have already imposed curbs. The southern financial centre of Shenzhen last month said it would ban new additions and ordered companies to take action to deal with misplaced, badly parked bikes throughout the city, which have become a health and safety hazard.

Shenzhen police are also ordering shared bike users who violate rules to write out a 1,000-word traffic regulation by hand or pay a 2,000 yuan (S$416) fine, the local Shenzhen Daily reported last week.

According to the Ministry of Transport, the cities of Shanghai, Hangzhou, Guangzhou, Fuzhou, Zhengzhou and Nanjing have also suspended all new shared bike additions.