China's central bank barred financial institutions from handling bitcoin transactions, moving to regulate the virtual currency after an 89-fold jump in its value sparked a surge of investor interest in the country.

Bitcoin plunged more than 20 percent to below $1,000 on the BitStamp Internet exchange after the People's Bank of China said it isn't a currency with "real meaning" and doesn't have the same legal status. The public is free to participate in Internet transactions provided they take on the risk themselves, it said.

The ban reflects concern about the risk the digital currency may pose to China's capital controls and financial stability after a surge in trading this year made the country the world's biggest trader of bitcoin, according to exchange operator BTC China. Bitcoin's price jumped more than ninefold in the past two months alone, prompting former Federal Reserve Chairman Alan Greenspan to call it a "bubble."