There are currently 13 million unique Xbox Live users playing Call of Duty 4: Modern Warfare, according to a new interview with Infinity Ward community manager Robert Bowling.

Speaking to Larry "Major Nelson" Hryb in his latest podcast, Bowling commented that: "Call of Duty 4 on Xbox Live just exploded. I mean right now we're at 13 million unique users on 360 and that's insane."

In January, Bowling put the online total for the Xbox 360 at 10,006,606 unique users, suggesting a considerable increase over the last few months - despite the game having been originally released in November 2007.