Regulators fined Alibaba a record $2.8 billion over the weekend for stifling competition in online retail, then met with affiliate Ant on Monday and ordered it to restructure as a financial holding company.

Then on Tuesday, the State Administration for Market Regulation warned 34 Chinese “internet platforms” in a meeting to learn from the crackdown on Alibaba and submit a plan for compliance with anti-monopoly practices within a month.

Chinese regulators have focused their attention in recent months on Jack Ma’s e-commerce giant and its fintech affiliate Ant Group, whose giant IPO was abruptly suspended in November. Authorities had begun investigating Alibaba in December, primarily for a practice of forcing merchants to choose one of two platforms, rather than allowing them to work with both.

The details of the 12 corporate pledges released Wednesday varied by line of business, and generally discussed efforts to support fair competition and protection of consumer data. The companies listed included Baidu, JD.com, Meituan, antivirus software company Qihoo 360, Twitter-like social media platform Sina Weibo, TikTok parent ByteDance, group buying e-commerce site Pinduoduo, electronics retailer Suning and e-commerce company Vipshop.

The announcements are the first in a series of such pledges set to come over the next three days, the regulator said.

Other U.S. or Hong Kong-traded names mentioned in Tuesday’s list of 34 internet platforms that were not included in Wednesday’s initial round included iQiyi, Bilibili, Kuaishou, Mogu and 58.com.

— CNBC’s Arjun Kharpal contributed to this report.