A double decker bus has crashed into a railway bridge with its roof tearing off in Glasgow city centre.
The 4A First Bus became wedged under the bridge on Cook Street at the junction with Commerce Street at about 18:00.
Police and ambulance crews are on the scene. Firefighters were also sent but are now leaving the area.
Spike Turner, a passenger who was third from the front of the bus, said the driver had taken a wrong turn and crashed "straight into the bridge".
The street is one-way and the bridge, near the O2 Academy is located shortly after a turn - though is clearly marked for vehicles under 3.8 metres (12.5 ft).
Mr Turner said: "I was fine, the lady in front of me might have been concussed. The bridge itself wasn't high enough to hit anyone's heads but parts of the bus exterior have swung down.
"The man in the front seat was in a really, really bad state. He's got a lot of blood and a massive gash on his head."
The extent of injuries are not yet clear.
ScotRail has closed a number of lines due to the crash.
A spokesperson said train services between Glasgow Central and Ardrossan Harbour, Ayr, Largs, Gourock, Wemyss Bay and Paisley Canal will be cancelled, delayed or revised.
Police have sealed off Cook Street at Centre Street, Commerce Street until Wallace Street and Salkeld Street to Cook Street.
A spokesperson for the force urged drivers to avoid the area.
First Bus, Network Rail and the Scottish Ambulance Service have been approached for comment.
In May last year, 10 people were taken to hospital after a bus crashed into the same railway bridge.
Additional reporting by Paul English