LOS ANGELES, Dec. 29 (UPI) -- Two medium-size earthquakes rattled northern and southern California on Tuesday within 15 minutes of each other, officials said -- putting emergency personnel on alert in a region famously susceptible to tectonic activity.
The first earthquake, measured at a magnitude of 4.9, occurred off the northern California coast at 5:35 p.m. local time. The epicenter was recorded about 60 miles northwest of Eureka, the San Francisco Chronicle reported.
Tuesday's was the second earthquake in the area in as many days. A 4.8-magnitude quake struck in virtually the same location Monday evening, officials said.
The second quake struck at about 5:45 p.m. about 50 miles east of downtown Los Angeles, data from the U.S. Geological Survey indicate.
The epicenter of the quake, measured by the USGS at a magnitude of 4.4, was recorded near Devore in the San Bernardino area. A series of strong aftershocks followed, officials said, and people felt shaking as far away as Burbank to the north and San Diego to the south, KTLA-TV reported.
The earthquake had a depth of about 3 1/2 miles, the USGS said.
Two aftershocks were measured at magnitudes of 3.8 and 3.2 and occurred within a few hundred feet of the initial earthquake.
The Los Angeles Fire Department said on Twitter it was in "earthquake mode."
"All 106 fire stations will survey their district to ensure safety for all," the department said on its website.
No injuries or damage were initially reported.
Tectonic activity is common along the state of California due to numerous fault lines, including the famed San Andreas. More than 3,000 people died in the 7.9-magnitude 1906 San Francisco earthquake. Other deadly quakes have struck in recent decades, including the 6.9-magnitude 1989 Loma Prieta earthquake and 6.7-magnitude 1994 Northridge quake.