The death toll from an explosion at a hydroelectric plant in Italy rose to five on Thursday as rescuers found two more bodies, with two workers still missing, according to statements from the fire service.

Since the blast occurred on Tuesday at Enel Green Power's (EGP) Bargi plant on Lake Suviana near Bologna, emergency services have been methodically descending nearly a dozen floors below water level.

Approximately 100 firefighters, including 12 divers, continued their efforts on Thursday, as confirmed by fire service spokesperson Luca Cari to Agence France-Presse (AFP). He also verified the updated death count.

Bologna's prefect, Attilio Visconti, said Wednesday that the turbine explosion happened on the eighth floor below water and resulted in five injuries.

The cause remains undetermined. However, Visconti confirmed flooding on the ninth floor due to a turbine cooling pipe, which brought in several meters of water.

The incident has raised fresh questions about workplace accidents in Italy. Five people died after a building collapsed at a Florence construction site in February, and five maintenance workers were killed by a train last August.

EGP, the renewables unit of energy giant Enel, has pledged its full cooperation with authorities in establishing the cause of the "serious accident."

The firm announced on Wednesday a 2 million euro ($2.14 million) fund for the urgent needs of victims and their families.

It had previously said that "efficiency works" were underway at the time of the blast, being carried out by three subcontractors.

"There was no safety problem; it was an intervention planned since September 2022," EGP head Salvatore Bernabei told Italian media.

He said it was "a normal technological update that is done in power plants."

Prosecutors in Bologna are investigating.

As of the end of 2021, Italy had 4,646 hydroelectric plants, which are mainly in the country's north and represent more than 14% of national consumption.