Rome - The number of dead following this week's Genoa bridge collapse could rise further, as state prosecutors spoke of several more people missing under the rubble.

"There could be another 10 to 20 missing persons," lead prosecutor Francesco Cozzi said on Thursday in the Italian port city, according to the ANSA news agency.

Hopes of finding survivors were dwindling

Cozzi had placed the death toll at 42 on Wednesday, while local authorities could only confirm 38 deaths.

Rescuers worked through the night with sniffer dogs, the fire brigade wrote on Twitter on Thursday, adding that search operations continue. But two days after a section of the Morandi motorway bridge crashed 45 metres to the ground, bringing more than 30 cars down with it, hopes of finding survivors were dwindling.

Regional Governor Giovanni Toti was quoted by ANSA as saying that, as the hours passed, "it is not very likely to find survivors."

There were varying reports about the length of the section of the bridge which collapsed during stormy weather, ranging from 100 to 250 metres. A reliable source said on Thursday that it was a 180-metre stretch of road.

Among the dead were at least three children, aged 8, 12 and 13. Fifteen people were injured according to local authorities, nine of whom are still in critical condition.

Trans-European Transport Networks

The bridge was part of the Trans-European Transport Networks (TEN-T) and was therefore subject to special test and safety requirements of the European Union, the bloc's executive said on Thursday.

But the Italian authorities were responsible for implementing these requirements, the European Commission said.

The commission rejected claims from Italy's eurosceptic Deputy Prime Minister and Interior Minister Matteo Salvini that EU-imposed spending rules were partly to blame for poor health and safety in the country's infrastructure.

EU states are welcome to set their own priorities within the budget rules, a commission spokesman stressed.

Critique of Autostrade per l'Italia

Motorway operator Autostrade per l'Italia has also come in for intense criticism. It had commissioned for later this year a 20-million-euro makeover of its concrete beams, which are suspected to have broken and caused the tragedy.

The government has blamed Autostrade and wants to revoke its licence for the motorway.

The company said on Thursday that it invested more than a billion euros annually in maintaining the bridge between 2012 and 2017. State prosecutors had previously said such an accident was unlikely.

Hundreds of people have been made homeless by the catastrophe after houses near the crash site were evacuated for safety reasons.

"There is a risk the other parts of the bridge could fall," a rescuer was quoted by ANSA as saying.

The government declared a 12-month state of emergency on Wednesday for the city of Genoa and announced 5 millions euros in emergency funding.