A motorway bridge has collapsed in the northwest Italian city of Genoa, sending vehicles plummeting up to 90m (295ft) to the ground and killing at least 22 people, officials say.

Video footage appears to show one of the towers holding up the suspension bridge collapsing in stormy weather.

Vehicles fell along with bridge debris on to rail tracks and a warehouse, reports the BBC.

Emergency workers are trying to free people caught in crushed vehicles or rubble, and are using sniffer dogs.

Transport Minister Danilo Toninelli spoke of an "immense tragedy" and France offered Italy its support.

Shares in Atlantia, the toll road operator which runs much of the country's motorways, fell 6.3% after news of the collapse.

French President Emmanuel Macron has tweeted a message of sympathy to the people of Italy, writing in both Italian and French. He said France was ready to offer any necessary aid.

It fell around 11:30 local time (09:30 GMT) during heavy rain. Police reported a violent cloudburst.

"It was just after 11:30 when we saw lightning strike the bridge," eyewitness Pietro M all'Asa was quoted as saying by Italy's Ansa news agency. "And we saw the bridge going down."

Another witness, unnamed, recalled: "We heard an incredible roar and first we thought it was thunder very close by.

"We live about 5km [three miles] from the bridge but we heard a crazy bang... We were very scared... Traffic went completely haywire and the city was paralysed."

Giving the death toll of 22, Deputy Transport Minister Edoardo Rixi said the number was likely to rise.

A child was among the dead and at least 13 more people were injured, said the head of the civil defence agency, Angelo Borrelli.

The Morandi Bridge, built in the 1960s, stands on the A10 toll motorway, which serves the Italian Riviera and southern coast of France.

BDST: 2045 HRS, AUG 14, 2018
AP