A person has died following a crash between a 52-seater coach and car that saw a driver cut free and airlifted to hospital.
Ten people have been taken to hospital after the Cleddau Bridge crash in west Wales, with one critically injured.
A major incident was declared by fire crews after a driver was trapped and “many” bus passengers suffered injuries in the crash on Tuesday at 14:15 BST.
The main road between Pembroke Dock and Milford Haven is partially closed.
Wales’ First Minister Mark Drakeford has said that it is “worrying to hear news of a major incident on the Cleddau Bridge” in Pembrokeshire.
“My thoughts are with all those involved and my thanks to the first responders and emergency services working at the scene,” he said.
The local health board has asked people to only attend the nearby Withybush Hospital in Haverfordwest if they have a life-threatening illness or serious injury.
Hywel Dda health board said that would enable staff to help with the emergency response.
“Crews responded to a road traffic collision involving one 52-seater bus and one private motor vehicle,” Mid and West Wales Fire and Rescue Service said.
Fire crews cut free “a severely trapped driver” who was later flown to hospital by air ambulance.
“Several of the bus passengers suffered with various injuries and many of them were taken to hospital by road ambulances and police vehicles,” the statement added.
The air ambulance and five emergency land ambulances attended the scene on Tuesday afternoon as fire crews worked to free the trapped driver and also gave first aid to injured passengers.
The main A477 road from Pembroke Dock to Milford Haven and Haverfordwest is shut westbound.
Pembrokeshire council has, however, said the bridge is partially open eastbound but “can only be accessed via Burton”.
“Roads are expected to be extremely busy, please take extra care,” added the council statement.
Lauren Joseph was trying to cross the bridge after work, travelling to her home near Milford Haven just after the crash – and faces an hour-long, 35-mile diversion.
“As I got there the council advised me to go the long way around at the Carew roundabout due to an incident,” she said.
“I am currently doing 20mph on a 60mph because of the congestion caused by the crash.”