According to the news a bitcoin exchange close its services and other exchanges say they do not receive any instructions from central bank of china and they are working normally but the rumors push the investors to sell bitcoin which leads bitcoin prices to go down. I think if the investors study and watch the market properly the prices will go up.
This is the way to make another down easily. The prices of bitcoins were going up high so panic was created. As you said, Central Bank of China did not announce any orders regarding it but rumors were created and things are against the odd. Better luck to bitcoins.