Strong earthquake off Guatemala-Mexico coast

TAPACHULA, Mexico (Reuters) - A strong 6.5-magnitude earthquake struck in the Pacific near the Mexico-Guatemala border on Thursday, but there was no tsunami alert and no initial reports of casualties.

The U.S. Geological Survey said the quake was 40 km southwest of the Mexican city of Tapachula, on the border with Guatemala, with a depth of about 75 km.

"Fortunately, no victims or damage has been reported in the city or the rural area," said civil protection official Herbert Schoeder in Tapachula, where people ran out on the streets in alarm as buildings began shaking.

A Reuters reporter in Guatemala City said he felt shaking for 30 seconds, but there appeared to be no major damage and no reports of casualties, according to the Guatemalan emergency services.

The Pacific Tsunami Warning Center said there was no threat of a destructive Pacific-wide tsunami.

Earthquakes above magnitude 6 can cause widespread damage in populated areas. Thursday's quake was initially measured at magnitude 6.7.

Heavy rain in recent weeks has left rural parts of Guatemala prone to mudslides.

"This kind of earthquake could result in damage. The edges of roads in mountainous areas are unstable," said Raul Mazariegos, a spokesman at Guatemala's natural disasters institute.

Three years ago, mudslides killed hundreds of people in Guatemala, where many live in poor hillside villages that are hard for rescue workers to reach.

(Additional reporting by Daniel LeClair and Sarah Grainger in Guatemala City and Cyntia Barrera in Mexico City)