A magnitude 3.6 aftershock struck the Imperial Valley and eastern San Diego County Saturday, according to automated seismographs and computers operated by the U.S. Geological Survey.
The aftershock was centered about 30 miles south-southeast of Mexicali, or about 110 miles southeast of San Diego. It hit at 12:01 p.m.
And a magnitude 1.8 quake, with an epicenter near the junction of Interstate 8 and state Route 98, struck at 12:39, the seismographs reported.
Thousands of similarly-sized aftershocks have rattled the area since a magnitude 7.2 earthquake struck April 2, killing two people in Mexicali and severely damaging canals, schools and older buildings in Imperial County.