Valve announces 'Left 4 Dead 2'

Valve has announced that it is currently working on a sequel to co-operative first-person-shooter Left 4 Dead.

During Microsoft's keynote presentation at E3, it was revealed that Left 4 Dead 2 will be released for Xbox 360 and PC on November 17 this year.

The new game will involve a fresh collection of characters, who attempt to navigate a zombie outbreak on their way to New Orleans.

New weapons will include a sniper rifle, baseball bat, axe and frying pan, while an improved targeting system will let players more easily aim for individual limbs and appendages.

Another addition will be the so-called gauntlet sections where players have to reach checkpoints whilst being swamped by enemy forces.

Valve has reportedly opted to develop the sequel in order to host new gameplay innovations that could not be supported by the existing system.

This will involve a more sophisticated AI system to provide a stiffer challenge for the player.