China on Monday went further to prevent gaming addiction among minors by slashing the time they can spend on online games to only three hours per week.

Users under the age of 18 can only play online games from 8 p.m. to 9 p.m. on Fridays, weekends and official holidays, according to a document released by China's National Press and Publication Administration.

Real-name registration and logins will be strictly implemented, said the notice, adding that companies cannot offer games to users who fail the identification process.

China has tightened controls on online games for minors in recent years. In 2019, the country cut time limitations to 1.5 hours per day and three hours on weekends and holiday.

Earlier this month, the Xinhua-affiliated Economic Information Daily labeled in an article online games a "spiritual opium" that harms China's teenagers.

Tech giant Tencent, labeled as one of the "troublemakers" in the article, soon vowed to push for stricter curbs on teenagers' access to its flagship mobile game, "Honor of Kings."

The company said it would start with "Honor of Kings" to reduce teenagers' time playing video games and ban children under 12 from spending money on the games.

On Tuesday, "Honor of Kings" said it would abide by the new rules, continuously upgrade anti-addiction measures, and temporarily shutdown its standalone mode.

"Considering that the income contribution of teenagers from mobile games and online games is relatively low, it (the restriction) will not pose a large impact on companies' performances," said Meng Lei, China Equity Strategist at UBS, in a conference call on Tuesday.

In the second quarter, players under 16 accounted for 2.6 percent of Tencent's domestic gross gaming receipts, according to the company.

NetEase, another Chinese internet company, which gets 70 percent of its revenue from online games, said users under 18 account for less than 1 percent of its total game revenue.

"At present, the data we estimate is that the financial impact (from the rules) is less than 1 percent," NetEase CEO Ding Lei said in a conference call on Tuesday after the company released its second-quarter performance.

"Most of the changes will be seen in the traffic. For example, when the population of game users decreases, it may have a partial impact on the activity of game players," Meng said, adding that changes in corporate valuation and profit "needs to be further measured."