The quake was centered about 20 miles southeast of the border town of Mexicali at a depth of 4.3 miles, according to the U.S. Geological Survey. The epicenter was 23 miles south-southeast of the U.S. city of Calexico.
The latest temblor comes three days after the Mexicali area was rocked by a magnitude-5.4 quake that shut down factories and left 400,000 people without power.