Australia’s internet watchdog raised fears on Wednesday that popular online gaming platforms such as Roblox and Minecraft were being used by “predatory adults” to target children.

The nation’s eSafety Commission has sent legal notices to a host of the world’s most popular gaming platforms, demanding they explain how they are working to stamp out dangerous content.

Australia is at the forefront of global efforts to protect children from online harm, enacting laws last year that ban teenagers under 16 from social media.

eSafety boss Julie Inman Grant said research had shown the vast majority of Australian children played some sort of online game.

“Predatory adults know this and target children through grooming or embedding terrorist and violent extremist narrative in gameplay,” she said.

Online gaming platforms Roblox, Minecraft, Fortnite and Steam will be required to show how they are identifying and eliminating online harms, Inman Grant said.

“We’ve seen numerous media reports about grooming taking place on all four of these platforms, as well as terrorist and violent extremist-themed gameplay.”

Inman Grant said examples included gaming platforms recreating mass shootings and World War II concentration camps.

Roblox said it had policies in place that strictly prohibited extreme content.

“We welcome engagement with eSafety on this important topic,” the platform told AFP in a statement.

“We encourage anyone who sees anything concerning on Roblox to report it to us.”

Australia in December banned under-16s from a raft of the world’s most popular social media sites, citing the need to protect young minds from “predatory algorithms” filled with sex and violence.

Three months since the landmark laws came into effect, Australia’s online safety watchdog found a “substantial proportion of Australian children” were still scrolling banned platforms.