A 6.5-magnitude earthquake struck this afternoon in the Pacific off the western coast of Guatemala, the U.S. Geological Survey reported.

Striking about 17 miles (27 kilometers) below sea level, the tremor was centered about 19 miles west-southwest of Champerico, Guatemala, and 115 miles from the capital, Guatemala City. The quake was not far from southern Mexico, with the USGS reporting it was 27 miles south-southeast of the border community of Suchiate, Mexico.

Earlier Sunday, the U.S. agency had said it was a 6.2-magnitude tremor, but later revised the report with the higher magnitude. It was followed by a number of significant aftershocks with magnitudes as strong as 5.0.

The Pacific Tsunami Warning Center said that "based on all available data, a destructive Pacific-wide tsunami is not expected."

Sunday's earthquake is the second major one in four days to strike the region.

Last Wednesday morning, a powerful 7.4-magnitude tremor struck in the same area - about 22 miles from the coastal town of Champerico - at a depth of 15 miles. At least 52 people were killed in its aftermath, according to President Otto Perez Molina. Hundreds more were injured, while more than 2,200 homes were damaged.

That earthquake was the strongest to hit Guatemala since 1976, when one with a magnitude of 7.5 killed about 23,000 people, Molina said.