(CNN) -- A fourth earthquake in 24 hours rattled coastal Chile early Monday, according to the U.S. Geological Survey.
The magnitude 6.6 quake struck about 60 miles (97 kilometers) west of the city of Talca at 12:40 a.m. local time.
There were no immediate reports of damage.
The three other quakes -- all measuring between 5.6 and 6.0 -- were centered near Concepcion off the coast of Chile's Bio-Bio region on Sunday morning, about 80 miles south of the Talca earthquake.
The quakes follow an even stronger tremor -- a magnitude 6.8 -- that hit nearby on Friday, rattling the nerves of Chileans who have memories of a deadly quake from a year ago.
After Friday's quake, residents of coastal towns near Concepcion self-evacuated, and images from Concepcion showed hundreds of people crying in the streets after fleeing office buildings and high-rise apartments.
The city is still rebuilding from a 8.8-magnitude earthquake that struck in February 2010, killing hundreds.