Syracuse, Sep 10 (IANS/AKI): Two workers died late Wednesday when they fell into an industrial sewage tank at a chemical company in Sicily owned by Italian oil and gas giant Eni.

The two workers tumbled into the tank as they were carrying out a maintenance inspection at an ethylene plant at Eni's chemicals company Versalis, with the help of a robot.

The two men were identified as Salvatore Pizzolo and Michele Assente, both in their thirties, who were employed by an engineering firm.

Trade unions at the Priolo Gargallo petrochemical complex near Syracuse called a strike on Thursday to protest the fatal accident, many of which occur in Italian workplaces each year.

"We express our closeness to the families," said a union statement.

"Once again there is a tragedy waiting to happen due to the continuous absence of checks when assigning contracts".

One of the men slipped into the tank as they were setting up a small CCTV camera by its edge and his workmate fell in while trying to help him, according to judicial sources.

Co-workers made unsuccessful attempts to revive the two men with heart massage after pulling them out of the tank.

"The company offers its most heartfelt condolences to the families involved in this tragic incident," Eni said in a statement.

The energy giant said it was investigating the accident and would report its findings as soon as they were available.