Facebook, busy developing more private and encrypted communication across its apps, has lost two of its top executives -- Chief Product Officer Chris Cox and WhatsApp Vice President Chris Daniels, CEO Mark Zuckerberg has announced.

Embroiled in data privacy scandals amid the unabated spread of fake news on its platform, Facebook has lately seen several high-profile exits, including Jan Koum and Brian Acton, co-founders of WhatsApp.

"Cox and I have worked closely together to build our products for more than a decade and I will always appreciate his deep empathy for the people using our services and the uplifting spirit he brings to everything he does," Zuckerberg said in a blog post late Thursday.

In a separate Facebook post, Cox said Facebook is turning a new page in its product direction, focused on an encrypted, interoperable, messaging network.

"It's a product vision attuned to the subject matter of today: a modern communications platform that balances expression, safety, security, and privacy.

"This will be a big project and we will need leaders who are excited to see the new direction through," wrote Cox, who was one of the first 15 engineers Facebook hired 13 years back.

Zuckerberg also announced the departure of Chris Daniel, who helped Facebook define the business model for WhatsApp going forward.

"Daniel has also done great work in many roles, including running our business development team, leading Internet.org, which has helped more than 100 million people get access to the Internet," said the Facebook CEO.

Daniel was in India last year where he met IT Minister Ravi Shankar Prasad to discuss ways to sanitise WhatsApp amid several lynching episodes that happened owing to the spread of rumours on the platform.

"Will Cathcart will be the new head of WhatsApp. Most recently, he has done a great job running the Facebook app," Zuckerberg informed.

Fidji Simo will be the new head of the Facebook app.

"The leaders of Facebook (Fidji Simo), Instagram (Adam Mosseri), Messenger (Stan Chudnovsky), and WhatsApp (Will Cathcart) will report directly to me, and our Chief Marketing Officer (Antonio Lucio) will report directly to Sheryl (Sandberg)," Zuckerberg announced.

Last year, Instagram co-founders Mike Krieger and Kevin Systrom quit after reportedly facing issues with Zuckerberg.

Koum and Acton, co-founders of WhatsApp, quit to pursue other ventures, as Zuckerberg plans to merge all its apps into one unified experience.