Superintendent Samuel Gadingan, Panabo City police chief, said all the fatalities were connected with the Holy Cross of Davao College (HCDC) in this city.
The schools comptroller, Sister Mary Grace Parreñas, was among those killed.
Parreñas, together with teachers and employees not only of HCDC but also of the schools other branches such as the Holy Cross of Camudmud in Samal Island and Holy Cross of Calinan district here, had come from an extension community service in Tagum City when the tragedy happened.
Gadingan said a motorcycle suddenly crossed the path of the Kia van, causing it to swerve to the other lane and smash into a JRC passenger bus, which was on its way to Sto. Tomas town from Davao City.
The Panabo incident happened barely a few hours after another van, a Mitsubishi L-300, fell into a ravine in Mawab town in neighboring Compostela Valley, leaving seven people dead and 13 others injured.
The HCDCs human resources department identified the fatalities as Dorotea Pestaño, Diana Pestaño, Tristan Malabares, Domisiano Malon, Corazon Digal and Eufemio Digal, all from Holy Cross of Camudmud; Parreñas, driver Ricardo Roa, teacher Reynaldo Pono and his son Jasray, all from HCDC; and Rogelio Bujian of Holy Cross of Calinan.
Five others in the HCDC van survived the accident. They were identified as Rhodora Catubog, Rita Malabarbas, a certain Villaveles, Mederden Pedrosa and Mark Pedrosa.
Gadingan told The STAR the passengers of the JRC bus also suffered injuries and were treated in different hospitals.
The driver and passenger of the motorcycle are reportedly also in critical condition.