According to local media, the bus was traveling to Guatemala City from the town of San Agustin Acasaguastlan in El Progreso department, about 90 kilometers (56 miles) to the northeast.
A bus carrying 75 people plunged into a ravine in Guatemala City on Monday, killing at least 31 people and leaving others trapped under the wreckage in a river, rescue workers said.
The bodies of 36 men and 15 women were taken to a morgue set up for the accident, according to Guatemala City fire department spokesman, Carlos Hernández.