Dozens die as bus plunges off cliff in western Guatemala

A bus carrying scores of passengers plunged off a steep cliff in western Guatemala, leaving at least 43 people dead - including newborn babies - and injuring 40 others, officials said.

President Otto Perez Molina declared three days of official mourning for Monday's tragedy, one of the deadliest in the Central American nation in years.

The red bus fell 100 metres down the canyon and came to rest next to a river in the municipality of San Martin Jilotepeque, 64 kilometres west of the capital, Guatemala City.

Rescue workers installed cables between the banks of the river to move the bodies on stretchers above the water, their grim task becoming more difficult as it started raining. Residents who rushed to the scene volunteered to help rescuers pull victims stuck in the wreckage.

The government said the cause of the accident was not yet known and an investigation was under way following initial reports of a brake malfunction.

Survivors said the bus was overloaded when it crashed, according to local media.