A biker who collided with a bus on the A470 between Builth Wells and Erwood was flown to hospital by an air ambulance.
The crash, which happened yesterday on Hay Road by Chapel House - known locally as Abernant Bends, involved the biker on a Suzuki motorbike and a Scania bus.
The condition of the biker, who was treated by flying medics at the scene before he was taken to hospital, is unknown.
Police also attended the accident, which happened around 2.30pm, along with two ambulances and two fire crews.
A spokesman from Wales Air Ambulance said: “I can confirm that we attended the scene of a road traffic collision in the Builth Wells area yesterday.
“The charity’s Welshpool-based aircraft was tasked to the scene and arrived at 3.10pm
“The Welsh Flying Medics treated a patient on the scene who was then flown to the University Hospital of Wales, Cardiff.
“The aircraft left the scene at 3.47pm and arrived at hospital at 4.14pm. The crew then cleared the mission at 5.03pm.”
A Dyfed-Powys Police spokeswoman confirmed it was the biker who had been taken to the hospital.
A spokeswoman from the Mid and West Wales Fire and Rescue Service said that while two crews attended the accident, it was for area control as fuel had leaked from both vehicles into the road.
One of the attending crews, which was the first on the scene, was from Builth Wells and the other was from Talgarth.
She said: “Nobody was trapped, we were there to make sure the area was safe because liquid had leaked in the road.”The road was closed in both directions with drivers being diverted via the B4567 near Llanfaredd, however it did reopen three hours later.