The boys apparently ignited several illegal fireworks in Sign Hill Park at about 4:40 p.m., South San Francisco police Sgt. Bruce McPhillips said.
The fireworks started a fire in a south-facing portion of the park, and all of the boys fled without reporting the incident, he said. The fire was reported by a bystander, and firefighters responded and quickly contained the flames before they spread out of control, McPhillips said.
Investigators identified one of the boys, who told police the names of the others who were involved, McPhillips said.
Four of them are South San Francisco residents, and one lives in San Francisco.
All five were cited for conspiracy and burning property, and were released to their parents.