New Delhi, June 1 -- Malaysia on Monday began enforcing rules barring millions of children younger than 16 from owning social media accounts, joining a global effort to tighten online safety protections for young users.

The rules require social media platforms to implement age-verification systems and block users under 16 from creating accounts. They apply to platforms with at least 8 million users, including Facebook, Instagram, TikTok and YouTube.

Companies that fail to comply could face penalties of up to 10 million ringgit ($2.5 million). But parents whose children manage to bypass the law will not be penalized.

The government said the measures are aimed at protecting children from harmful content, cyberbullying and platform featur...