6.8 quake shakes southern Mexico

(CNN) -- A 6.8 magnitude earthquake shook southern Mexico's Guerrero state Thursday, less than a month after an even stronger temblor hit the area, the U.S. Geological Survey said.

Thursday's quake, centered about 65 miles northwest of Acapulco and 188 miles southwest of Mexico City, happened at noon local time, the USGS said.

On April 18, a major quake -- 7.2. magnitude -- hit the same state, but there were no reports of major damage that day.