Eddy Sanchez, director of the Guatemala's National Institute of Seismology, Volcanology, Meteorology and Hydrology (Insivumhe), told reporters that the quake had a magnitude of 7.2 degrees on the Richter scale.
The director said the quake's epicenter was in the Pacific Ocean off the beaches of Champerico, in the department of Retalhuleu, 34 miles (54.4 kilometers) deep and at a distance of 200 kilometers southwest of Guatemala City.
The USGS has said the quake was at 7.4 magnitude and struck at 1635 GMT at a depth of 41 km, with its epicenter in the Pacific Ocean, about 24 km southwest of Champerico, Guatemala.
Thousands of Guatemalan people have taken to the streets in fear of a new earthquake, and employees of public buildings have been evacuated for safety.
There's no tsunami threat to the Pacific region from this quake, according to the Pacific Tsunami Warning Center's latest bulletin.
Earlier on Wednesday, Molina has decreed a red alert across the country.
"Red alert is declared across the country, public activities are suspended and we recommended that all buildings be evacuated. We await official data and information in order to provide necessary assistance to all those affected," said the president.
Landmark building should respect the public's feeling