GUATEMALA CITY (Reuters) - A strong earthquake off the coast of Guatemala killed at least 39 people on Wednesday, trapping others under rubble, crushing homes and cars, destroying roads and forcing evacuations as far away as Mexico City.
Many of the dead were buried under debris in San Marcos state, a mountainous region near the Mexican border. Landslides triggered by the 7.4 magnitude quake blocked highways and complicated rescue efforts.
It was the strongest earthquake to hit the Central American nation since 1976, when a 7.5 magnitude quake killed more than 20,000 people.
President Otto Perez, who flew into the affected region by helicopter, said that as many as 100 people were unaccounted for, based on reports from relatives.
"It's very sad to meet people here who are waiting to find their families who are still buried," Perez said in San Marcos. "It's really a tragedy and we will do all we can to help the families that are suffering."
Television footage showed collapsed buildings and vehicles crushed under rocks and stuck in large cracks in highways.
In San Cristobal Cucho, in San Marcos state, all but one of an 11-member family died, buried under rubble, volunteer fireman Ovidio Fuentes told local radio. Only the 17-year-old son survived.
Local Red Cross chief Carlos Enrique Alvarado said 75 homes were destroyed in the city of San Marcos alone and authorities said damage to the prison forced them to transfer 101 inmates to another jail.
Perez said Spain and Venezuela had offered help. Authorities distributed 16,000 emergency rations and mobilized more than 2,000 soldiers to help with the rescue effort. The energy ministry said 73,000 people were left without electricity.
In Guatemala City, 100 miles (160 km) from the quake's epicenter, the streets were filled with office workers forced to evacuate buildings, although most soon returned to work.
"It was really big. I felt quite nauseous," said Vanessa Castillo, 32, a secretary 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 epicenter was 26 miles (42 km) below the surface, according to the U.S. Geological Survey.
The quake was felt in El Salvador and more than 760 miles (1,200 km) away in Mexico City, where some people also fled offices and homes.
The Pacific Tsunami Warning Center said a small tsunami was registered on Guatemala's coast, although there were no reports that it caused any damage. (Additional reporting by Nelson Renteria in San Salvador.; Writing by Krista Hughes; editing by Kieran Murray and Christopher Wilson)