SAN DIEGO (CNS) - A burning car alongside state Route 52 sparked a blaze that blackened about eight brushy open acres on the northern edge of Mission Trails Regional Park Tuesday afternoon.

Flames engulfed the unoccupied sedan on the eastbound side of the freeway near Mast Boulevard about 2:45 p.m., according to the San Diego Fire-Rescue Department.

By the time firefighters arrived, the blaze had spread to brush alongside the freeway and was moving to the south into the open-space preserve north of San Carlos, SDFRD spokesman Maurice Luque said.

It took ground crews and personnel aboard a water-dropping helicopter about a half-hour to stop the spread of the fire, which burned underneath some power lines but apparently did no harm to them.

No structural damage or injuries were reported.