“The current number of bodies recovered is 12,” Ivica Dacic told public broadcaster Radio Television of Serbia, revising upwards an earlier toll of eight dead and warning of other likely fatalities. “This number will not be final,” the minister added.

“The operation is still ongoing and extremely challenging. Over 80 rescuers are involved, with the assistance of heavy machinery,” Dacic said Friday afternoon.

The Blood Transfusion Institute in Novi Sad also called on residents to donate blood following the accident.

Serving Serbia’s second-largest city, the station reopened in July after three years of renovation work. Construction was still ongoing in parts of the station.

Serbia’s Prime Minister Milos Vucevic vowed that authorities would investigate the cause of the accident.

Serbia Railways said in a statement that the collapsed roof had not been part of the renovations completed at the station. “Serbia Railways regrets the accident that occurred, and the causes and any new details from the investigation will be promptly announced,” the company wrote in a social media post.