A vegetation fire is burning on the south end of Camp Pendleton, according to officials.
The fire started around 2:45 p.m. at the south quarter of the base, and heavy smoke is visible.
Firefighters evacuated the waste water treatment plant as a precaution.
Three firefighters have suffered injuries from smoke inhalation and heat. Two other crew members had minor injuries and were treated on site.
"The fire does not currently pose a threat to base residents or the surrounding community," said a statement from Camp Pendleton.
Camp Pendleton fire crews are battling the blaze at the scene and the fire is 80 percent contained.
Check back for updates on this story.
Keep up to date on breaking news: Download our improved iPhone app, follow us on Twitter @nbcsandiego, fan us on Facebook, sign up for our breaking news e-mail alerts or text SDBREAKING to 622339 to receive text messages for local breaking news. (For more info, text HELP. To end, text STOP. Message and data rates may apply.)