GUATEMALA CITY (Reuters) - A strong earthquake off the coast of Guatemala shook buildings in the capital and killed at least 39 people on Wednesday, trapping others under rubble and triggering evacuations as far away as Mexico City.
The 7.4 magnitude quake hit at 10:35 a.m. local time (1635 GMT). A local fire chief said at least some of the dead were buried under debris in a mountainous region near the Mexican border.
Landslides blocked roads in some areas, authorities said, and about 40 houses were severely damaged.
It was the strongest earthquake to hit Guatemala since a 7.5 magnitude quake in 1976 that claimed more than 20,000 lives.
President Otto Perez said that as many as 100 people were unaccounted for, based on reports from relatives.
"These are preliminary figures and we don't have them confirmed," Perez said in Guatemala City. "Our priority is to focus on lives, rescuing people and treating the wounded."
San Marcos state governor Luis Rivera confirmed the deaths of 39 people, adding that the state government offices were almost completely destroyed.
Perez said there had been five aftershocks, with authorities distributing 16,000 emergency rations and mobilizing more than 2,000 soldiers to help with the rescue effort.
Local fire chief Cecilio Chacaj said the bodies of 18 dead had been pulled from rubble in San Marcos and Quetzaltenango, the country's second largest city.
The quake struck off Guatemala's Pacific coast, 15 miles (24 km) south of Champerico and 101 miles (163 km) west-southwest of the capital, the U.S. Geological Survey said.
Evacuations in Guatemala City filled the streets with office workers calling friends and relatives on their cell phones, but people soon returned to work.
"It was really big; I felt quite nauseous," said secretary Vanessa Castillo, 32, who was evacuated from her 10th floor office in Guatemala City.
Building janitor Jorge Gamboa said: "I was in the bathroom. When I came out the office was empty and I thought, what's happening? They didn't even say goodbye."
The epicentre was 26 miles (42 km) below the surface, according to the USGS, which initially reported the quake as magnitude 7.5.
The quake was also felt in El Salvador and more than 765 miles (1,232 km) away in Mexico City, where some people also fled offices and homes. Mayor Marcelo Ebrard said the quake was felt strongly in a large part of the city of 20 million people.
The Pacific Tsunami Warning Centre said a small tsunami was registered on Guatemala's coast, adding that there was a risk of localized damage within a 62 mile (100 km) radius.