A bus has plunged off a mountain road in southern Brazil and into a river bank, killing 9 people and injuring at least 25 others, including children.

The bus company Reunidas says the driver was also killed in the Sunday accident after the vehicle veered off the road near the city of Alfredo Wagner and fell 165 feet down the bank. Seven people died at the site, including a boy, and two more perished later at the hospital.

Reunidas' lawyer Vinicius Marins says the cause is not known yet. The 25 people who were injured remained in local hospitals, he says.

The bus was traveling from the city of Posadas in Argentina to the southern coast of Florianopolis in Brazil. All of those killed and injured were Brazilian.