The accident occurred near the town of Motozintla when the bus ferrying people home from a spiritual retreat on the Pacific coast came off the road and fell down a steep slope, emergency services in the state of Chiapas said in a statement.
The passengers came from the nearby municipality of La Trinitaria and at least 17 died and another 31 were injured, said a spokesman for emergency services, Daniel Cuate.
It was not immediately clear what caused the accident.
President Enrique Pena Nieto expressed his condolences to the families of the bereaved on Twitter.
(Reporting by Dave Graham; Editing by Paul Tait and Louise Heavens)
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)
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