Call of Duty creator Infinity Ward is reportedly working on a fourth entry in the Call of Duty: Modern Warfare series, according to two separate sources.

First up, GamingIntel has heard that Call of Duty: Modern Warfare 4 is not only in development, but will apparently be a 'full fledged' affair complete with a traditional campaign, multiplayer, and Zombies.

Battle royale is reportedly also in consideration, but nothing has been set in stone as of yet.

Meanwhile, CharlieIntel has also heard similar murmurs about next year's Call of Duty game. The reports also come in light of recent news that a number of key developers who left Infinity Ward to join Respawn back in 2010 have apparently returned to the studio to work on the franchise once more.

Call of Duty: Modern Warfare 3 was released in 2011 for PlayStation 3, PC, and Xbox 360, and appeared to close off the trilogy. It's also been reported that Activision will be remastering Call of Duty: Modern Warfare 2, though nothing official has been confirmed as of yet.

This year's entry is being handled by Treyarch in shape of Call of Duty: Black Ops 4.