China’s market regulator on Tuesday tightened scrutiny over the country’s booming livestream e-commerce platforms, where internet influencers sell goods directly to consumers, citing concerns about poor quality products and misleading advertising.

The State Administration of Market Regulation (SAMR) recently met several livestream e-commerce companies, which presented self-disciplinary measures, the agency said in a statement, without naming the firms.

It said all livestream platforms should “quickly conduct self-control and comprehensive inspections” on product quality, and should punish livestreamers who sell shoddy goods.

The move is the latest in a series of measures by the regulator to rein-in a thriving “platform economy,” which includes popular livestream e-commerce platforms run by internet giants such as Alibaba’s Taobao, Kuaishou and ByteDance’s short video app Douyin.

Alibaba, ByteDance and Kuaishou did not immediately respond to requests to comment.

Since last year, increasingly vigilant Chinese regulators have launched a probe into e-commerce giant Alibaba Group and imposed penalties on Alibaba, Baidu and Tencent for not seeking anti-trust reviews for acquisitions and corporate tie-ups.

Other firms have been fined for unfair competitive behaviour.

By Yingzhi Yang and Tony Munroe; Editing by Andrew Heavens and Edmund Blair.