Chad Coleman (Tyreese), Sonequa Martin-Green (Sasha) and Emily Kinney (Beth) will have a major presence when the zombie drama returns in October, with Melissa Ponzio (Karen) set as a recurring guest star.

AMC's The Walking Dead is firming up its ranks for season four.

Just days after the zombie drama's bloody season finale, the show based on the comics created by Robert Kirkman has promoted three familiar faces to series regular.

New additions Chad Coleman (Tyreese), Sonequa Martin-Green (Sasha) and Emily Kinney (Beth) will rejoin the series full time when The Walking Dead returns in October, The Hollywood Reporter has learned. They join David Morrissey (The Governor) as regulars on the series, which will start off next season at the newly repopulated prison.

PHOTOS: 'The Walking Dead's' Most Shocking Deaths

In addition, Melissa Ponzio -- who plays Karen, the lone survivor of the Governor's attack on his own Woodbury army that helped bring peace between Tyreese and Rick in the finale -- will return to the series as a recurring guest star in season four.

Coleman joined the series in November in a recurring role as fan favorite Tyreese, who first appeared in the seventh issue of Kirkman's long-running Image comic. During season three, Tyreese played a central role in saving the women and children of Woodbury from the Governor, rejoining Rick -- with his outspoken sister, Sasha (Martin-Green), who is a new character to the Walking Dead universe.

STORY: 'Walking Dead' Dissection: Robert Kirkman on the Major Fatalities and Comic Book Detour

Kinney, who plays Hershel's youngest daughter Beth, has been with the series since the second episode of season two and likely will continue to have a larger story as she helps the group care for Rick's (Andrew Lincoln) newborn daughter, Judith, and someone who's closest in age to his troubled son, Carl (Chandler Riggs).

"[Rick] is letting the people of Woodbury in and trying to tell Carl that these people are like us, you have to be open to this and the only way to survive in this world is to have people and be in a community. That's going to be a big part of season four," Kirkman told THR after the finale, which claimed the lives of Milton (Dallas Roberts) and Andrea (Laurie Holden).

PHOTOS: 'The Walking Dead's' Most Shocking Deaths

During its record-breaking third season, The Walking Dead lost a long roster of characters. In addition to Holden -- who had been with the series since its 2010 premiere -- Rick's wife Lori (Sarah Wayne Callies) shockingly was killed off in early in its third year along with regular T-Dog (IronE Singleton), among other recurring players including Daryl's (Norman Reedus) brother Merle (Michael Rooker). The additions help firm up the show's ranks as returning villain the Governor is still hungry for Michonne (Danai Gurira) and Rick's blood.

Kinney is repped by Abrams Artists, Authentic Talent and Literary; Coleman is with Talent Works and Vanguard; Martin-Green is with Gersh and Principal Entertainment; and Ponzio (Teen Wolf, The Following) is with People Store and Kass Management.

The Walking Dead returns to AMC in October with new showrunner Scott M. Gimple.

Email: Lesley.Goldberg@thr.com; Twitter: @Snoodit