Naughty Dog has confirmed that The Last of Us has been censored in Europe.
A community manager answered a private message from a user, and their response was posted on the Naughty Dogs forums:
“The gore and violence ratings are subject to local regulatory boards in various countries, so the game must be slightly changed in order to accommodate those choices,” the representative wrote.
As a result, the European, Australian and PAL versions of the game are missing certain elements of gore in multiplayer mode. The Last of Us's single-player campaign remains uncut.
For more information, check out this forum thread over at the Naughty Dog forums.