4.0 magnitude earthquake strikes near Palomar Mountain in north San Diego County

SAN DIEGO (KABC) -- A 4.0 magnitude earthquake struck near Palomar Observatory in northern San Diego County on Sunday morning, the U.S. Geological Survey said.

"We felt an earthquake here at NWS San Diego--it looks like the preliminary estimate is 4.1 near Palomar Mountain," the National Weather Service said on Twitter. "There were 2 main jolts with a rapid shaking."

The quake struck at 9:46 a.m. and was centered about 18 miles southeast of Temecula and 18 miles northeast of Escondido, according to the USGS.

The agency initially recorded the temblor's magnitude at 4.1; it was later downgraded to 4.0

There were no immediate reports of injuries or damage.

"Felt it in Aliso Viejo," Kristine Bolbolan said on Facebook. "Light shaking and the door rattled for a good 15 seconds."