A strong earthquake shook Guatemala and El Salvador Thursday, but there were no immediate reports of injuries or damages.

In El Salvador, the quake registered at 6.0 on the open-ended Richter scale at 8:47 a.m., according to the Earthquake Information Center in Golden, Colo.In Guatemala City, people fled screaming into the streets when the tremor was first felt there at 9:10 a.m.

The Colorado center said the quake was centered 60 miles southwest of San Salvador off the coast of Central America.

A spokesman at the center said he had no information about the earlier temblor felt in Guatemala and was not sure whether there had been a second, earlier, quake.

Salvadoran radio broadcasts said the tremor lasted for about 10 seconds.