Sources have also told ABC News that an incendiary device was found in the blue van.
On Sunday, police distributed DVDs featuring footage of a man, between 20 and 30 years old with a receding hairline and a shoulder-length ponytail, whom they described as a person of interest.
He was seen on grainy surveillance video Saturday after emerging on foot from inside an underground parking structure on Hollywood Boulevard where a car fire was reported.
Early today, firefighters battled 12 suspected arson fires at carports and garages. Ten occurred in Los Angeles and two were in West Hollywood.
Authorities believe the latest fires are connected to the earlier ones. The number of suspicious fires now stands at 55.