A passenger bus lost control and veered off a road and into a 75-foot-deep (25 meter-deep) gully in southern Mexico early Wednesday, killing at least 29 passengers, officials said.

The crash occurred in the largely indigenous Mixteca region of the southern state of Oaxaca.

The state's interior secretary, Jesús Romero, said 27 people had died in the crash, including a 1 1/2-year-old toddler. He said that about 20 people were injured in the accident, some very seriously.

His office later said the death toll had increased to 29, after two victims died from their injures at a hospital.

Romero said the bus driver apparently lost control of the vehicle and plunged into the gully.

“It appears that a lack of skill and tiredness caused the accident,” Romero said in remarks to a local television station.

Photos distributed by police suggesting the bus had flipped over, totally crushing the passenger compartment.

The bus set out from Mexico City to carry passengers to a number of tiny, remote mountain villages in the impoverished Mixteca region.

The route, and the possessions, bundles and baskets strewn amid the wreckage, suggested the victims were people who worked in manual labor in the capital and were returning to their home towns.