The fourth phase of World of Warcraft's elemental invasion has started with the major cities now coming under attack. We've got a guide up detailing the new bosses and how to defend your cities from falling to the new elemental threat.

The fourth and supposedly final phase of World of Warcraft’s elemental invasion event has begun. The major cities are now being assaulted by legions of elementals while more trouble brews in the various dungeons littering Azeroth. It’s up to brave adventurers in each city to mount a defense and then lead a counter attack to stop these invasions.

Phase 4 of the Elemental Invasion has begun. Get out there and defend your cities.