A major bridge has collapsed in the US city of Baltimore after it was hit by a cargo ship.
Footage shows a large section of the 1.6 mile-long Francis Scott Key Bridge falling into the water following the collision at around 1.30am local time (5.30am UK time).
Vehicles can be seen in the video falling from the bridge.
Baltimore's fire service said emergency teams were searching for at least seven people.
Chief Kevin Cartwright, director of communications for the Baltimore City Fire Department, said its main focus right now was "trying to rescue and recover these people".
He said it was too early to know how many people were affected, but described the collapse as a "developing mass casualty event".
Mr Cartwright said it appears there were "some cargo or retainers hanging from the bridge," creating unsafe and unstable conditions, and that emergency service workers were operating cautiously as a result.
"This is a dire emergency," he added.
The container ship, known as the Dali, was headed to Colombo in Sri Lanka at the time of the collision.
Data from MarineTraffic showed the Singapore-flagged ship came to a halt at the bridge.
The first ship to arrive at the scene around 10 minutes later was tug Eric Mcallister, according to the data.
It was joined by a second tug Bridget Mcallister, alongside a search and rescue vessel, around 25 minutes after the bridge was hit.
At least 10 boats are currently involved in the rescue operation.
A spokesperson for Baltimore Police Department told Sky News' US partner network NBC News: "I can confirm at 1.35am, Baltimore City police were notified of a partial bridge collapse, with workers possibly in the water".
Baltimore's mayor, Brandon M Scott, said emergency personnel were on the scene and rescue efforts were under way.
Johnny Olszewski, Baltimore county executive, said he was in contact with the chief of the fire department and the director of emergency operations.
"Please pray for those impacted," Mr Olszewski added.
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The Maryland Transport Authority said all lanes on the Interstate 695 - the road which runs across the bridge - were closed and traffic is being rerouted.
Built in 1977, the bridge is referred to locally as the Key Bridge.
It is one of the longest continuous truss bridges in the world, according to the National Steel Bridge Alliance.
( Skynews)
