At least two people were hospitalized with serious injuries after the incident in the city of Novi Sad.

At least eight people have died after a concrete roof over the entrance of a train station in the northern Serbian city of Novi Sad collapsed.

At least two other people were hospitalized with serious injuries on Friday, Serbian Interior Minister Ivica Dacic said.

The minister said rescuers were in contact with two people who were still trapped under the rubble.

“The operation is still ongoing and extremely challenging. More than 80 rescuers are involved, with the help of heavy machinery,” he added.

Ambulances and other emergency crews were sent to the station in the city center and bulldozers were removing the debris in the search for survivors.

Surveillance footage showed people walking in and out of the building and sitting on benches on a bright, sunny day before the concrete canopy suddenly collapsed on them.

The station, the second largest city in Serbia, reopened in July after three years of renovation work. Construction work continued in parts of the station.

Dacic said the rescue operation was “extremely difficult” and would take at least several hours.

The Blood Transfusion Institute in Novi Sad asked residents to donate blood following the accident.

Serbian Prime Minister Milos Vucevic promised that the authorities would investigate the cause of the accident.

“We will insist on finding those responsible, those who should have ensured the safety of the structure. Condolences to the families of the deceased,” said the prime minister.

“This is a Black Friday for us, for all of Serbia, for Novi Sad,” he added.

Serbian Railways said in a statement that the outer roof that collapsed was not part of the renovations completed at the station. The accident is said to have occurred at 11:50 local time (10:50 GMT).

“Serbia Railways regrets the accident that occurred, and the causes and any new details from the investigation will be announced promptly,” the company wrote in a social media post.

Local media said dozens of people were injured. The city hall acknowledged the incident but did not say how many were injured.

The N1 news channel said train departures were halted from the station about 70 km (43 miles) northwest of the capital Belgrade.