'Game of Thrones' might spawn new HBO shows, says creator

FILE - In this March 18, 2014 file photo, author and co-executive producer George R. R. Martin attends the "Game of Thrones" fourth season premiere in New York. (Photo by Evan Agostini/Invision/AP, File)

NEW YORK -- HBO's "Game of Thrones" is in its home stretch. But the game isn't over for its creator, George R.R. Martin, who is in the thick of planning as many as five new "Game of Thrones"-related series for the network.

Posting on his website, Martin specified that each concept under development is for a prequel, not a sequel. He indicated any of the new series would be populated with fresh characters.

He noted that it remains to be seen how many of the pilot scripts currently being written will actually be filmed, and how many series might result from those filmed pilots. He says he is working with all the writers.

Just 13 episodes remain for "Game of Thrones," which HBO is splitting into two final seasons. It returns in July.