Italy has inaugurated a sleek new bridge in Genoa, though relatives of the 43 people killed when the old viaduct collapsed said the pomp and ceremony risked overshadowing the tragedy.

Jets trailing the colours of the Italian flag roared overhead and ship sirens sounded in the coastal city's port, almost two years to the day the Morandi overpass gave way during heavy rain, hurling dozens of cars and several trucks onto railway tracks below.

As a rainbow appeared in the sky, Italian Prime Minister Giuseppe Conte cut the ribbon on the new San Giorgio bridge, designed by famed Italian architect Renzo Piano.

He gave it a curved, gleaming underbelly evoking the hull of a ship in tribute to Genoa's maritime history.

"Forty-three stars will shine every night on high," Mr Conte said, as lamps along the bridge, numbered for the victims, lit up.

The Morandi bridge collapsed on 14 August 2018, killing 43 people

The names of the victims were read aloud - though many of their loved ones were not present.

"We won't be at the inauguration, we don't want the tragedy to be transformed into a carnival," said Egle Possetti, whose sister died in the disaster on 14 August, 2018, along with her husband and their two children.

Ms Possetti, a spokeswoman for a victims' relatives group, said she would "never" cross the bridge. "How could you be there and not think of everything that happened, and destroyed your family?" she said.

The Morandi bridge had been riddled with structural problems for decades, leading to expensive maintenance, and its collapse threw a spotlight on Italy's creaking infrastructure.

The tragedy also ended the longstanding concession of highway maintenance by a company majority-owned by the powerful Benetton family.

The new high-tech structure will have four maintenance robots running along its length to spot weathering or erosion, as well as a special dehumidification system to limit corrosion.

It is expected to open to traffic tomorrow or Wednesday.

Mr Piano, a Genoa native whose building designs include the Centre Georges Pompidou in Paris and The Shard in London, described his new creation as a "child born of tragedy, of mourning".

"We are suspended between grief and pride", he said while Prime Minister Conte hailed the new viaduct as "a sign of rebirth".

The Morandi was hailed a marvel of engineering when it opened in 1967, but an investigation into the disaster found it was neglected.

Italian Prime Minister Giuseppe Conte (C) with Genoa's Mayor Marco Bucci (R) and President of Liguria Region, Giovanni Toti at the inauguration ceremony of the new bridge

Autostrade, which runs almost half of Italy's motorway network, has been accused of failing to maintain it properly. Atlantia, the parent group of Autostrade, is controlled by the Benetton family.

It finally bowed to pressure last month to relinquish control of the toll operator firm, which will be nationalised.

Roberto Battiloro, father of a young videomaker who died along with three friends, said the families were "still waiting for justice".

"That bridge should not have collapsed, and someone has to pay," he said on Facebook.