A 3.8-magnitude earthquake struck near Corona at about 11:40 p.m. Wednesday. The U.S. Geological Survey said the temblor occurred at a depth of 5.3 miles.
There were no reports of any injuries or significant damage, but the quake was felt across the region, including Fontana, Riverside, San Jacinto, Lake Elsinore, Menifee, Murrieta, Temecula and Irvine.
The second quake had a magnitude of 3.2 and struck 2.3 miles north of Fontana at 1:50 a.m. Thursday. According to the USGS, the temblor hit about 5 miles west-northwest of Rialto and 6 miles south-southwest of Devore. The quake had a depth of about 1.1 miles.
There were no immediate reports of damage or injuries.
These quakes come after a larger 4.4-magnitude earthquake struck about 3 miles north of Fontana around 1:35 a.m. Wednesday. This quake had a depth of about 3 miles.
Friday marks the 20th anniversary of the magnitude-6.7 Northridge quake that left 57 people dead, more than 5,000 injured and more than $20 billion in property damage.