Forces of Chaos invading Warhammer 40K: Space Marine

You can add Chaos Space Marines to the list of things to kill in Warhammer 40,000: Space Marine. THQ confirmed today the Forces of Chaos will play a prominent role in the upcoming third-person shooter, making the million-odd feral Orks just one of the two major forces out make Captain Titus' life difficult in the single player campaign.
The inclusion of Chaos Space Marines to Relic Entertainment's forthcoming game will add an element of strategy to the action, balancing out the brutish mentality of the Orks with their cold, calculating maneuvers. The Forces of Chaos will also have support from a smattering of units including Renegade Militia, Tainted Psykers and Bloodletter Daemons.
The reveal came with a batch of new screenshots featuring the interdimensional army in all its glowing, misshapen might:

 

Warhammer 40,000: Space Marine tells tale of Captain Titus and his Ultramarines' plight to defend a 'Forge World' against an Ork invasion. It is being developed for PS3, Xbox 360 and PC, and is slated to make planet-fall this August.