Traffic ground to a halt in central London after Tower Bridge was left stuck open following a mechanical fault.
The famous bridge opened at around 4pm to allow a tall ship to pass along the Thames underneath.
But the arms, known as bascules, failed to close again afterwards and remained raised at odd angles.
Traffic and pedestrians were held back while mechanics scrambled to fix the mechanical fault, with some complaining of having to wait more than an hour to cross.
One tweeted: ‘I’ve been stuck here for nearly an hour now.’ Another said the bridge ‘opened almost an hour ago and it hasn’t closed back yet’, adding: ‘It looks stuck and the two patrts aren’t symmetrical.’
City of London Police said on Twitter: ‘Tower Bridge is currently closed to pedestrians and traffic, due to a mechanical fault. Mechanics are currently working hard to fix the bridge. Please find alternative routes.’
It is not the first time the landmark has suffered a technical glitch.
Engineers spent 10 hours trying to bring the arms down in 2005.
Each bascule weighs more than 12 tons, and a 400-ton counterweight helps lower them once river traffic has passed through.
Get in touch with our news team by emailing us at [email protected].
For more stories like this, check our news page.