Meta Platforms has paused hiring in its artificial intelligence division after bringing on more than 50 researchers and engineers, the Wall Street Journal reported on Wednesday.

The move comes amid growing global concerns that investment in AI is moving too fast. In July, Meta’s Mark Zuckerberg had pledged hundreds of billions for AI data centres in a “superintelligence push”.

The social media giant is among the large tech companies that have struck high-profile deals and doled out multi-million-dollar pay packages in recent months to fast-track work on machines that could outthink humans on many tasks.

“The hiring freeze, which went into effect last week and coincides with a broader restructuring of the group, also prohibits current employees from moving across teams inside the division,” according to the WSJ report.

“The duration of the freeze wasn’t communicated internally.”

“All that’s happening here is some basic organisational planning: creating a solid structure for our new superintelligence efforts after bringing people on board and undertaking yearly budgeting and planning exercises,” a spokesperson for Meta said in an emailed statement to Reuters.

Earlier this week, Meta had planned the fourth restructuring of AI efforts in six months, according to The Information.

“The company is expected to divide its new AI unit, Superintelligence Labs, into four groups: a new “TBD Lab,” short for to be determined; a products team including the Meta AI assistant; an infrastructure team; and the Fundamental AI Research (FAIR) lab focused on long-term research,” the report said.