ArmA 2's zombie mod, Day Z, has surpassed 500,000 players, a message on the game's official Twitter account has revealed.

"Congratulations everyone, with your support through tough times, mistakes, troubles, and technical problems, we now have over 500k users!" read the Tweet.

Only last weekend creator Dean Hall told a Rezzed audience that Day Z had reached 420,000 players. At the time the game was maxing out at 22,000 concurrent players at peak time and 10,000 off peak.

Day Z is a free mod for Arma 2. You'll find details on how to play over on the Day Z website.