
The quake, with a magnitude of 6.5, struck at 5.39am.
Its epicentre was in the Pacific Ocean 90km from the coast of San Marcos department and at a depth of 25km, the institute said.
A bulletin from the San Marcos government said no victims had been reported.
But the National Hospital of San Marcos suffered “slight damage”, according to the state Coordinator for Disaster Reduction.
It also reported three landslides on the Cito Zarco highway.
The authorities say 90% of Guatemala is prone to tremors, owing to the convergence of the Caribbean and Cocos tectonic planes, as well as local geological faults.
A 1976 quake of 7.5 magnitude claimed some 23,000 lives.