Italy’s Prime Minister says 22 people have been killed and 16 injured after a bridge collapsed in Genoa.

Giuseppe Conte travelled to the site of the disaster late on Tuesday in the port city, calling it an “immense tragedy”.

He told RAI state television “it is shocking to see the twisted metal and the bridge collapsed with victims who were extracted”.

Mr Conte also praised the hundreds of rescue workers still at the site, saying “they saved people who fell 45 metres and are now alive and in the hospital”.

A truck at the bridge edge
A truck stopped right at the edge of the area where the Morandi bridge collapsed (Vigili Del Fuoco/AP)

He added that the death toll is expected to rise further.

A huge section of the Morandi Bridge fell at midday over an industrial zone, sending tonnes of twisted steel and concrete onto warehouses below. Photos from the Italian news agency ANSA showed a massive gap between two sections of the bridge.

The head of Italy’s civil protection agency, Angelo Borrelli, said up to 35 cars and at least three trucks were on the 80-metre section of the span that collapsed.

Rescuers at work
Rescuers work in the debris (AP)

Hundreds of firefighters and emergency officials were searching for survivors in the rubble with heavy equipment. At least four people were pulled alive from vehicles under the bridge, ANSA reported.

Video of the collapse captured a man screaming: “Oh, God! Oh, God!”

Other images showed a green truck that had stopped on the bridge just short of the edge and the tyres of a tractor trailer in the rubble.

The Morandi Bridge
The bridge would have been busy with holiday traffic on the eve of a major festival (AP)

One man who was standing under the bridge in front of his truck when the bridge collapsed called it “a miracle” that he survived. The middle-aged man, who did not give his name, said the shockwave sent him flying over 10 metres into a wall, injuring his right shoulder and hip.

“I was in front of the truck and flew away, like everything else. Yes, I think it’s a miracle. I don’t know what to say. I’m out of words,” he said, walking away from the site.

The disaster occurred on a motorway that connects Italy to France, and northern cities like Milan to the beaches of Liguria. The Morandi Bridge connects the A10 highway that goes toward the French Riviera and the A7 highway that continues north toward Milan. Inaugurated in 1967, it is just over 6 miles long.

An injured man
Several people were injured in the disaster (AP)

French President Emmanuel Macron offered his country’s help in a phone call with Mr Conte.

It was the second deadly disaster on an Italian highway in as many weeks.

On August 6, a tanker truck carrying a highly flammable gas exploded after rear-ending a stopped truck and getting hit from behind near the northern city of Bologna.

The accident killed one person, injured dozens and blew apart a section of a raised eight-lane highway.