Nine people were killed and at least nine others injured when a bus plunged into a 300-meter (984-foot) ravine in Tolima, a province in southern Colombia, the highway patrol said Sunday.

The bus was carrying officials and relatives of employees of the Universidad Surcolombiana in Neiva, the capital of the neighboring province of Huila.

The accident occurred on Saturday night, a highway patrol spokesman said, adding that 19 people were aboard the vehicle when it went off the highway.

One person is listed as missing, the highway patrol spokesman said.

Emergency services personnel, Red Cross workers, National Police officers and army troops rescued the wounded and recovered the bodies.

Search teams are looking for the missing person, the highway patrol spokesman said.

The driver apparently tried to avoid a rock that had fallen on the highway and went off the road in the fog, officials said.

The university's provost, Julian Hernan Zambrano, and accounting chief, Magda Rocio Lozada, were among those killed in the accident.

The injured were taken to hospitals in Ibague, the capital of Tolima.