At least 25 people were killed in two separate bus crashes in Mexico on Monday, authorities said.

In the country's north, 14 people died in a fiery collision between a tractor-trailer and a bus carrying passengers from the US state of Texas, civil protection authorities in Durango state said.

Of the 24 people travelling in the bus, only 10 managed to get out alive, it said.

In southern Mexico, a bus turned over along a highway in Oaxaca state, killing 11 people, authorities said.

Twelve others were taken to the hospital with injuries, two of them in critical condition, the Oaxaca state government said in a statement.

"I extend my heartfelt condolences to the victims' families, to whom we will provide the necessary support and assistance during this difficult time," Oaxaca Governor Salomon Jara said on social media.

In a interview on local radio on Monday afternoon, the state's interior minister, Jesus Romero, said the bus was carrying more than 40 people and was en route to the Isthmus of Tehuantepec in Mexico's south.

Romero said it seemed that the passengers were heading home after attending a rally held on Sunday by President Claudia Sheinbaum in the capital Mexico City.

Authorities will launch an investigation into the cause of the accident, which happened near the community of Santo Domingo Narro, it said. (Agencies)