Instagram founders are leaving Facebook Inc. People close to this matter related the reason of this resignation as the growing tensions with CEO Mark Zuckerberg regarding the direction of the photo-sharing app.

Kevin Systrom and Mike Krieger, who have been present at the company since Instagram’s acquisition by Facebook in 2012, had been successful in differentiating the brand and product from Facebook. Lately, they were frustrated with an unusual uptick in day-to-day involvement by Zuckerberg, who is now placing more reliance on Instagram for Facebook’s future growth.

Now, minus the founders around, Instagram is likely to become more tightly integrated with Facebook. Thus, the people added that, this would be now more of a product division within the larger company than a separate app.

The founders Systrom and Krieger’s confirmed their decision of in a blog post, although Facebook didn’t immediately have a comment on this  tension.

To this, Zuckerberg added in a statement that, “Kevin and Mike are extraordinary product leaders and Instagram reflects their combined creative talents. I’ve learned a lot working with them for the past six years and have really enjoyed it.”

Six years back, Krieger and Systrom built Instagram and sold it to Facebook for $715 million. Instagram, which now has more than one billion users, is a key driver of revenue for Facebook.

Systrom’s statement on the Instagram read that, “We’re planning on taking some time off to explore our curiosity and creativity again. Building new things requires that we step back, understand what inspires us and match that with what the world needs; that’s what we plan to do.”

While Facebook’s name has been associated with scandals on privacy, fake news and election interference, off late, Instagram’s brand has remained mostly untarnished, and has continued to grow users rapidly. Facebook, which is now almost running out of people in the world to add to its product, has placed its greater reliant on the photo-sharing app for its future.

The company has started mentioning Instagram more frequently on its earnings calls and taking credit for its success. Also, in his most recent call, Zuckerberg explained that Instagram grew twice as fast being part of Facebook as it could have been on its own. This, many Instagram insiders felt was unnecessary.

Also, this departure of Instagram’s founders comes just weeks after Facebook decided to bring Instagram’s chief operating officer, Marne Levine, back to Facebook to become its global head of business development. The previous part of this year, saw  Adam Mosseri, who formerly ran Facebook’s news feed, was brought to Instagram to be the head of product. People related to the matter admitted him to be the most justified successor for the founders, though Facebook declined to comment on who might take over.

The year is not at all good for Facebook as within a year Facebook has lost several top executives at its biggest acquired properties. In fact, Brian Acton and Jan Koum, the founders of WhatsApp, also announced their departures after disagreements with Zuckerberg over the messaging application’s business model.