Two cars were discovered burning Thursday morning in Fullerton as the city's police department investigated a series of arson fires in the area over the last few months.
Police discovered two flaming vehicles in the 1200 block of Gilbert Street at around 1:13 a.m.
Firefighters had to intervene after officers tried to put out the flames with fire extinguishers, police said.
Police called the fires "suspicious," but have not linked it to this week's arson fires in the area.
Four trash bins were set on fire Tuesday on Gilbert Street and appeared to be connected to a series of arsons in the area since September 2016, police said.