According to On Location Vacation, production of Mockingjay will start by September 16, 2013 in Atlanta, Georgia. Los Angeles and Boston were also among the other locations for which the movies will be filmed. If you could still remember, there were also rumor that Mockingjay will be filmed in Bristol, England. You can read about that post here.
Access Atlanta has also reported before that scouts were seen in the north Georgia mountains. OLV has also added that there were already offices that were opened in EUE/Screen Gems Studios in Atlanta.
CL Casting is still handling the extras for the movie while the Crew Call handles the crews. In fact, they are searching for people who would like to participate in their team. In a recent article from Georgia.org, they said:
CREW CALL: “The Hunger Games: Mockingjay Part 1″
Accepting resumes for all crew positions. Please email your resume to email@example.com