Several small earthquakes hit the Inland Empire early Wednesday morning, but there were no reports of damage. Ontario saw two quakes — measuring 3.5 and 3.2 magnitude — just after 1 a.m. That was followed by a 3.

A light, 4.3-magnitude earthquake struck in Southern California on Thursday, according to the United States Geological Survey. The temblor happened at 9:32 a.m. Pacific time about 4 miles west of Muscoy, Calif., data from the agency shows. U.S.G.S. data earlier reported that the magnitude was 4.2.

The same region has been struck by a series of similar-sized earthquakes in recent weeks, when a 3.1-magnitude quake rattled Big Bear Lake in the San Bernardino Mountains and several different temblors struck on the same day centered near Rialto and Muscoy,

A magnitude 3.7 earthquake near Lytle Creek jolted awake residents across San Bernardino County, the latest in a string of quakes in Southern California.