Rihanna and Chris Brown have surprised fans by recording not one but two songs together.

The pair revealed their remixes of each other's songs last night.

While Rihanna posted a remix of her track 'Birthday Cake' on Twitter to coincide with her 24th birthday, Chris Brown followed suit by unveiling the remix to his new single 'Turn Up The Music' on his twitter page.

Brown wrote: "The pub and excitement of this industry /society is only a surface! Really want us as a human race to unite! Bigger than music! (sic)" 

Rihanna also wrote: "Its a download OVERLOAD!!!! Working on more links for u guys, so errbody could have some #CAKE" as she attempted to give fans links to the remix.

It had been rumoured that the two stars were planning a huge collaboration - with producer Da Internz also hinting there was a Rihanna collaboration in the works that would shock the world.

But with the release of their duets it now appears the infamous 2009 assault has been put behind them.

This is also the first time Rihanna and Chris Brown have also worked together since he featured on a remix of her 2007 smash hit 'Umbrella'.