China amended its tobacco monopoly law on Friday to include e-cigarettes, stepping up regulation of the fast-growing vaping industry in the world’s largest tobacco market.

The cabinet order, published on the Chinese government’s website and signed off by Premier Li Keqiang, comes into effect immediately.

In recent years, a number of Chinese ecigarette companies were established to capitalize on domestic sales. Among them is market leader RLX Technology Inc.

Chinese regulators had in March this year flagged plans to bring the rules governing the sale of e-cigarettes and other new tobacco products into line with those for ordinary cigarettes.

They were previously in an area of regulatory gray.

China’s tobacco industry is controlled entirely via a government monopoly, and strict controls determine which companies and retailers can produce and sell cigarettes.

The government outlawed the sale of e-cigarettes to minors in 2018 and banned online sales the following year, while Chinese state media have warned of the health and safety risks of using the products.