Firefighters said they battled two suspicious fires not far from each other overnight Saturday.
The fires broke out near Interstate 680 in Martinez, between the Benicia Bridge and Pacheco Boulevard.
Despite it being nighttime and cool outside, firefighters told NBC Bay Area the dry brush helped fuel the flames.
Crews were able to put out the flames before they got to nearby dog kennels and other buildings.
Investigators are now looking into whether someone purposely started those fires.