MARK Zuckerberg has escalated a war of words with Apple CEO Tim Cook, charging that Apple is “just serving rich people” with its pricey gadgets.

Facebook’s billionaire founder delivered the testy allegation in an interview overnight after Apple’s boss last week blasted the social network for violating users’ “human rights” for privacy by selling their data to third parties, reports the New York Post.

“You know, I find that argument, that if you’re not paying that somehow we can’t care about you, to be extremely glib. And not at all aligned with the truth,” 33-year-old Zuckerberg said in an interview with Vox.

“The reality here is that if you want to build a service that helps connect everyone in the world, then there are a lot of people who can’t afford to pay,” Zuckerberg added.

Last week, Cook made headlines when he said in an interview that Facebook’s recent Cambridge Analytica scandal has shown the social network needs government regulation.

Apple’s CEO said that the company views privacy as a “human right” and a “civil liberty.”

“The truth is we could make a ton of money if we monetised our customer, if our customer was our product,” Cook said. “We’ve elected not to do that.”

On Monday, Zuckerberg shot back at Apple and its notoriously expensive products, saying that Facebook’s goal is “to build a service which is not just serving rich people.”

“I think it’s important that we don’t get all Stockholm syndrome and let the companies that work hard to charge you more convince you that they actually care more about you,” Zuckerberg said. “Because that sounds ridiculous to me.”

Facebook shares were down as much as two per cent in the US overnight.