“To stay ahead of evolving security threats, we’re investing more in automated detection and bringing in new skills as we continue to grow our security team over all,” a company spokeswoman said in a statement. “This also means we are restructuring a portion of our team and helping the people affected by this change find other roles at Facebook.”

Facebook’s security efforts have increasingly come under scrutiny in the past few years. In 2016, Russians used the social network to sow divisive messages to sway voters in the American presidential election. In 2018, the company disclosed a security breach that left the accounts of tens of millions of people vulnerable.

Its security operations were previously housed together in one large group under Alex Stamos, the chief information security officer. After Mr. Stamos left Facebook in 2018, the security teams were reassigned and reported into different parts of the company, such as engineering and policy. Facebook has since eliminated the chief information security officer position.

Facebook is looking for new approaches to bolster security across its services, according to two of the people. That includes hiring software engineers to write programs that can carry out many of the security duties previously accomplished by humans, they said. Managers who supported an automated approach have said it will be easier to scale up over time, since training artificial intelligence to handle those duties will mean less reliance on people.