While not directly related to stock market sellers and short-sellers, perhaps a warning sign?

China has formally arrested a Guangzhou labor organizer and three other people authorities had been holding amid a crackdown on worker activism

The three have been charged with "disturbing social order"

Another activist was arrested on charges of embezzlement

More here

(As a ps. China stock markets re open after the weekend at 0130GMT, the yuan mid-point reference rate will be announced slightly before then, just after 0115GMT)