OCEANSIDE, Calif. — A possible arson fire scorched about an acre Wednesday on the outskirts of Mission San Luis Rey, spreading onto the grounds of a cemetery at the landmark 19th century church complex but causing no reported structural damage or injuries.

The blaze erupted near the intersection of state Route 76 and Rancho del Oro Drive shortly before noon, according to the Oceanside Fire Department.

It took firefighters about 15 minutes to fully extinguish the flames, OFD Battalion Chief Scott Stein said.

A man found near the origin point of the blaze was taken into custody on suspicion of igniting it, Oceanside police Lt. Kedrick Sadler said.

The suspect, whose name was not immediately released, was still being questioned in the late afternoon, the lieutenant said.

The cause of the fire was under investigation, Stein said.