At least 16 people have been killed and 36 more injured following a bus crash Tuesday on central Mexico’s Cuacnopalan-Oaxaca highway, according to officials.

The bus, which was carrying locals and migrants, collided with a trailer truck on the highway near the border between the states of Oaxaca and Puebla, Oaxaca’s Prosecutor’s Office said in a statement.

The traffic accident killed at least eight men and eight women, including one minor. The injured were transferred to hospitals in Puebla for medical attention.

The reason for the collision is unknown, but the prosecutor’s office has said they will conduct an expert-led investigation to uncover what events unfolded that led up to the crash and determine if anyone should be held liable.

“I have instructed the heads of the relevant authorities to collaborate and support the injured people,” the governor of Oaxaca, Salomón Jara Cruz, said on X, formally known as Twitter. “We send a hug and condolences to the families of the deceased, to whom we will also provide all our support.”

Puebla’s interior ministry said it is in communication with federal government agencies and state authorities on how best to support the victims.