Two earthquakes rattled Los Angeles within four hours, including one centered near the Baldwin Hills oil fields, but no injuries or damage were reported.
The second quake, magnitude 3.5, struck in the View Park-Windsor Hills area at 9:17 p.m. PDT on Sunday, the U.S. Geologic Survey said.
At 4:35 p.m., a magnitude 2.5 tremor shook Baldwin Hills area, about three miles away.
The epicenter was located near the Baldwin Hills oil fields, about eight miles west of downtown Los Angeles, raising speculation that the quake was caused by drilling, the Los Angeles Times reported.
But USGS seismologist Lucy Jones tweeted that the depth of the quake was well below the oil fields. She said that quake was considered a "foreshock" to the larger one because they were in the same area and struck within a few hours of each other.
The Los Angeles Fire Department went into "earthquake mode," meaning all 106 neighborhood fire stations surveyed the city for damage.
It said no damages or injures had been reported.