A 6.5-magnitude earthquake shook Guatemala's Pacific coastline on Sunday, four days after a major quake killed dozens in the Central American country.
People fled buildings and homes in panic in various cities along Guatemala's Pacific coast near its border with Mexico on Sunday, but there were no immediate reports of deaths or major damage.
Eddy Sanchez, director of Guatemala's National Institute of Seismology, Vulcanology and Hydrology, urged residents to avoid returning to buildings and homes with structural damage from the last quake.
The US Geological Survey said the quake's epicenter was 19 miles (30 kilometers) west-southwest of Champerico, Guatemala, and 185 kilometers (115 miles) southwest of Guatemala City.
It had a depth of 27 kilometers (17 miles) and was centered off the country's coast.
Seismologists say it was the strongest aftershock yet from a 7.4-magnitude earthquake that killed 52 people in western Guatemala on Wednesday.
That quake, the country's strongest in 36 years, left thousands of people without homes, electricity or water; and emotionally devastated one small town by wiping out almost an entire family.
It was felt as far as Mexico City. It affected as many as 1.2 million Guatemalans and was followed by 70 aftershocks in the first 24 hours.
Guatemalan President Otto Perez Molina had deployed more than 2,000 soldiers to the region to help with the disaster.
The US state department said it was sending some $50,000 in immediate disaster relief, including clean water, fuel and blankets.