SHANGHAI (Reuters) - Chinese authorities have ordered Beijing-based cryptocurrency exchanges to stop trading and immediately notify users of their closure, signaling a widening crackdown by authorities on the industry to contain financial risks.

Exchanges were also told to stop allowing new user registrations as of Friday, according to a government notice. The notice was signed by the Beijing city group in charge of overseeing internet finance risks and circulated online. A government source verified it to Reuters.

Platforms should also tell the government by Wednesday Sept. 20 how they will allow users to make withdrawals in a risk-free manner and handle funds to make sure investor interests are protected, according to the notice, which was also reported by state newspaper Securities Times.

“All trading exchanges must by midnight of Sept. 15 publish a notice to make clear when they will stop all cryptocurrency trading and announce a stop to new user registrations,” the government notice said.

China is cracking down on the cryptocurrency business to try to limit risks as consumers pile into a highly speculative market that has grown rapidly this year. Reuters and other media reported earlier this week that it planned to shut down the exchanges.

Shanghai-based BTCChina, a major Chinese bitcoin exchange, said on Thursday it would stop all trading from Sept. 30, citing tightening regulation. Smaller Chinese bitcoin exchanges ViaBTC, YoBTC and Yunbi on Friday announced similar closures.

Beijing-based platforms OkCoin and Huobi, which are among China’s biggest exchanges, said late on Friday that they planned to stop yuan-based trading by Oct. 31.

FILE PHOTO: An attendant holds a bitcoin sign during the opening of Hong Kong's first bitcoin retail store February 28, 2014. REUTERS/Bobby Yip/File Photo

By (10.06 a.m. ET) 1406 GMT, BTC’s price was down 7.63 percent at 19,797.00 yuan ($3,024.71).

The bitcoin price was down 5 percent at $3,071 at 1036 GMT on U.S. exchange Bitstamp. The bitcoin price index on trade website Coindesk slid below $3,000 for the first time in six weeks.

Bitcoin fell by more than 10 percent on Wednesday after a warning by JPMorgan Chief Executive Jamie Dimon that it “is a fraud” and will eventually “blow up”.

“ILLEGAL FLOWS”

Li Lihui, a senior official at the National Internet Finance Association of China and a former president of the Bank of China, told a conference in Shanghai that global regulators should work together to supervise cryptocurrencies.

“Digital tokens like bitcoin, ethereum that are stateless, do not have sovereign endorsement, a qualified issuing body or a country’s trust, are not legal currencies and should not be spoken of as digital currencies,” he said.

“They can become a tool for illegal fund flows and investment deals.”

He said there should be a distinction between digital currencies, which were being studied and developed by authorities such as the Chinese central bank, and digital tokens such as bitcoin. Digital currencies developed by authorities could be used for good, with the right regulation, he said.

The state-backed internet finance body was set up by the central bank, and its members include banks, brokerages, funds and consumer finance companies. On Wednesday, it urged members to abide by Chinese laws and not deal in cryptocurrencies.

Since January, Chinese bitcoin exchanges have rolled out a series of changes to comply with increased scrutiny by Beijing. But they were thrown into chaos on Sept. 4 when China issued a directive banning initial coin offerings (ICOs).

China’s crackdown “is all about protecting market stability and protecting the interest of investors, so halting these kinds of initial coin offerings is a very necessary action,” Li said.

Vlad Zamfir, a researcher at the Switzerland-based Ethereum Foundation, told Reuters that it was no surprise China is moving against such currencies. Beijing has capital controls, he said, that are “in direct tension with the free ability to send any amount of money anywhere without any kind of delay”.