The China Securities Regulatory Commission said it will step up a crackdown on fake news and rumors about policies that move financial markets, according to an agency statement published late Friday.

The move came after China’s stock market took a dive earlier this week, triggered by rumors involving newly appointed CSRC Chairman Yi Huiman.

News circulated online Tuesday that Yi was scheduled to hold his first press conference that day with policy announcements targeting short-selling and financial fraud involving listed companies.

The news, which later proved to be false, dragged down the Shanghai index by nearly 2% in a couple of hours.

The CSRC said Friday that falsifying market information violated the country’s Securities Law and would be subject to severe punishment.