A railway bridge in south-eastern Norway that ran across a river swollen by torrential rain has collapsed, authorities said.

Bane NOR, a government agency in charge of the Norwegian rail infrastructure, said the central section of the steel truss bridge over the Laagen River slid into the water “due to damage to the central bridge foundation”.

All traffic across the bridge was halted a week ago out of fear that it would collapse because of the large volume of water.

“Bane NOR had just begun investigating the extent of the damage to the bridge on Monday morning when the middle part slid into the river,” the agency said in a statement.

A section of a railway bridge collapsed into the water over the Laagen River in Ringebu, Norway
A section of the railway bridge collapsed into the water over the Laagen River in Ringebu, Norway (Geir Olsen/NTB Scanpix via AP)

The bridge is 172.5 metres (189 yards) long with three spans.

It has a direct foundation on the riverbed, and was built in 1957.

Eivind Bjurstrom, at Bane NOR, said the collapse of the bridge “never involved a danger to life and health, which I am very happy about”.

The rain led to the evacuation of thousands of people in south-eastern Norway, where a huge amount of water, littered with broken trees, debris and rubbish, thundered down the usually serene rivers after days of torrential rain.

A section of a railway bridge collapsed into the water over the Laagen River in Ringebu, Norway
All traffic across the bridge was halted a week ago (Geir Olsen/NTB Scanpix via AP)

Storm Hans battered northern Europe, leading to transportation disruption, flooding and power cuts across the Nordic and Baltic region.

At least three people were killed.

A hydroelectric river dam in south-eastern Norway collapsed as water forced its way through, and a train derailed in neighbouring Sweden when a railway embankment was washed away by floods.