India, April 1 -- Australia's online safety watchdog said on Tuesday that it was considering court action against Facebook, Instagram, Snapchat, TikTok and YouTube, alleging they are not doing enough to keep Australian children younger than 16 off their platforms.

Experts say the Australian courts could decide what steps the platforms can reasonably be expected to take under the laws that took effect on Dec. 10, banning young children from holding accounts.

eSafety Commissioner Julie Inman Grant on Tuesday released her first compliance report since those laws took effect, demanding that 10 platforms remove all Australian account-holders younger than 16.

While 5 million Australian accounts had been deactivated, a substantial number of A...