A bus crash on the outskirts of Mexico City killed 18 people on Sunday, while another 32 were injured, according to the state of Mexico's civil protection agency.

The accident happened in Malinalco in the southern region of Mexico state, which surrounds the capital on three sides, when a bus traveling from San Luis de la Paz, in Guanajuato State in central Mexico, to the Chalma sanctuary south of Mexico City, overturned on the highway.

Fourteen people were killed instantly, while another four died later in hospital, according to the state of Mexico's secretary of security.