At least 25 people were killed and 23 others injured in a bus accident over the weekend in the western Mexican state of Guerrero, emergency management officials told Efe.

The accident happened around 1:30 p.m. Sunday on the highway that links the cities of Tlamacazapa and Buenavista de Cuellar.

The bus flipped over and slid into a 200-meter (656-foot) ravine, deputy state emergency management secretary Constantino Gonzalez Vargas said.

The 48 passengers had just attended a rally staged by the Workers Party, or PT, one of the parties in the coalition backing presidential candidate Andres Manuel Lopez Obrador.

State emergency management officials, ambulances, firefighters and paramedics responded to the accident.

The injured were transported to hospitals in the cities of Taxco, Iguala and Buenavista de Cuellar. EFE