More than 4.7m social media accounts held by Australians who platforms have judged to be under 16 years of age were deactivated, removed or restricted in the first days after the ban came into effect in December, the prime minister has said.

After the social media ban came into effect on 10 December, the eSafety commissioner sent questions to each of the platforms covered by the ban asking how many accounts had been removed in order to comply with the law.

The 10 platforms the government announced were covered by the ban were Twitch, Kick, YouTube, Threads, Facebook, Instagram, Snap, X, TikTok and Reddit.

According to data received in response to these questions, released by the prime minister on Thursday, more than 4.7m accounts were deactivated, removed or restricted in the first few days of the ban.

The government cited commercial confidentiality in declining to break down the number of accounts affected on each platform, however, Meta on Monday said it had deactivated almost 550,000 accounts across Facebook, Instagram and Threads.

Guardian Australia has sought comment from other platforms regarding their individual numbers.

_{Sign up: AU Breaking News email}

The prime minister, Anthony Albanese, said preliminary analysis from eSafety suggested the platforms were preventing users from holding accounts.

“It’s encouraging that social media companies are making meaningful effort to comply with laws and keep kids off their platforms,” he said.

“Change doesn’t happen overnight. But these early signs show it’s important we’ve acted to make this change.”

The communications minister, Anika Wells, said eSafety would examine the data to see what it shows about the compliance of individual platforms.

“We’ve said from the beginning that we weren’t expecting perfection straight away – but early figures are showing this law is making a real, meaningful difference.”

The federal opposition, which campaigned for the policy before it was adopted by the government, last week said the ban implementation had “fallen flat”.

“Many under-16 accounts have not been deactivated, while others that were initially removed have since become active again,” the shadow communications minister, Melissa McIntosh, said.

“New accounts are being created and the age-verification tools that the government assured Australians would be effective, have proven laughably easy to bypass with some makeup and good lighting.”

McIntosh said children who lost access had migrated to other platforms such as Yope and Lemon8, arguing they were not included in the ban.

The ban requires all platforms to self-assess as to whether the ban should apply to them, and the government indicated it would approach other platforms to seek compliance should teens migrate to those platforms.

Some platforms such as X alternative Bluesky implemented age-assurance despite not being initially named in the list released by the government.

While the UK and other countries are considering following Australia’s lead, a new study on Wednesday tracking 11 to 14-year-olds in the UK found no evidence for boys or girls that heavier social media use or more frequent gaming increased teenagers’ symptoms of anxiety or depression.

It found social media use from year 8 to year 9 and from year 9 to year 10 had no detrimental impact on their mental health the following year.