A bus crash in the south of Mexico on Friday killed 18 Venezuelan and Haitian migrants and left 27 others injured, state authorities said.

Among the dead are 13 men, two women and three children, according to the attorney general’s office in the state of Oaxaca, where the crash occurred.

It said the 27 injured people were taken to nearby hospitals, but did not specify their nationalities.

Photos from the Oaxaca state civil protection agency show the bus, which was traveling on the highway connecting Oaxaca and the central state of Puebla, tipped over along a tight curve in the road.

The accident comes amid high levels of migrants arriving at the U.S.-Mexico border. Migrants attempt to cross Mexico by bus, in trucks or aboard cargo trains. However, the journey is often dangerous.