HONG KONG (Reuters) - Tencent Holdings, China’s biggest gaming and social media firm by revenue, said it will limit play time for some young users of “Honour of Kings”, responding to complaints that children were getting addicted to the popular mobile game.

A child plays the game "Honour of Kings" by Tencent at home in Dezhou, Shandong province, China July 2, 2017. REUTERS/Stringer

Parents and teachers have complained that children were becoming addicted to the multiplayer online battle game, which, according to the company, has more than 200 million users, mostly in China, and is the top-grossing mobile game in the world.

From Tuesday, users below 12 years of age will be limited to one hour of play time each day, while those aged between 12 years and 18 years will be limited to two hours a day, Tencent said. Tencent did not say whether the limits will be imposed only in China or elsewhere too.

The firm also plans to ban users under 12 years from logging in after 9 p.m. (1300 GMT) and will impose further restrictions on how much money younger users spend on the game, it added.

The fantasy role-playing game based on Chinese historical characters is the world’s top-grossing game by worldwide iOS + Google Play revenue in May, according to mobile data intelligence firm App Annie’s latest monthly index. It grossed on average $84 million per month on iOS in China in the first five months of the year, App Annie data showed.

More than half of its users are below 24 years of age, including more than a quarter below 19 years, according to Chinese mobile data firm Jiguang.

The game, which involves violence, became the subject of controversy after Chinese media reports in recent months of serious addiction to it among young people.

“There are no rules to prevent indulgence in mobile games in China, but we decided to be the first to try to dispel parental worries by limiting play time and forcing children to log off,” Tencent said on its official WeChat account.

Tencent, which has a portfolio of over 200 games, also said it would upgrade a parental-control platform rolled out earlier this year that makes it easier for parents to monitor their children’s gaming account activities.

It will also step up the requirement of real-name registration for all users, it said. Accounts that do not provide real-name information will be treated as below-12, Tencent said.

Chinese gaming industry database CNG estimates the game raked in a revenue of more than 5.5 billion yuan ($810.47 million) in the first quarter, accounting for nearly half of Tencent’s smartphone games revenue of 12.9 billion yuan in the period.

Tencent declined to comment on the estimates.

Honour of Kings doubled its monthly active users to 163 million in the past six months, according to Jiguang, while China’s mobile gaming revenue grew by 4.5 billion yuan to 27.5 billion yuan over the period, the biggest growth in two years, according to CNG.

China is the world’s largest gaming market by revenue, and is expected to account for roughly 25 percent of global game sales in 2017, according to research firm NewZoo.