Zach Roerig and Candice Accola on December 17, 2009 in Sonoma, California. Credit: Christopher Polk/WireImage

Zach Roerig and Candice Accola have moved on.

A source tells Us Weekly that the Vampire Diaries costars have broken up.

Accola, 25, plays Caroline Forbes on the hit CW show and Roerig, 27, plays Matt Donavan. The costars had kept their relationship offscreen fairly low-key.

In October of last year, Accola tweeted a photo of Roerig, writing, "Cheering on my man at his second paddle board race! He kicked some major a**."

Roerig also tweeted a photo of Accola wearing a bikini on the beach with "Go Zach!" written across her stomach. "My number one cheerleader!" he wrote.

On May 3, the CW announced Vampire Diaries has been picked up for a fourth season.