MEXICO CITY -- At least 11 people were killed in a collision early Saturday in the municipality of Penjamo, central Mexican state of Guanajuato, said local authorities.

The civil protection authorities of Penjamo reported that the accident occurred at 1:30 a.m. local time (0730 GMT) on highway 90 connecting the town with the city of La Piedad in the neighboring state of Michoacan, when a tractor hit a minivan-type truck with those victims on board.

Local media reported that 10 people lost their lives inside the truck and another one passed away when receiving medical treatment after being rescued by firefighters from the wreckage of the vehicle.

Preliminary data collected at the site indicated that the 11 passengers killed were relatives.

Police and the prosecutor's office of Guanajuato continued to work at the scene as part of the investigation underway to find the cause of the accident.