A 55-year-old man has been taken to hospital after falling approximately 20 metres down an embankment in Brynaman.
A rescue mission was underway with emergency service teams at the scene on the A4069 Brynaman to Black Mountain.
Police assisted with road closures and rope rescue teams were present.
Fire crews from Pontardawe, Amman Valley and Brynaman were all called to the incident.
A Welsh Ambulance Spokesperson said: “We were called at shortly after 1pm this afternoon to reports that a motorcyclist had left the road on the A4069 in Upper Brynaman.
“The Wales Air Ambulance and two crews in emergency ambulances are currently at the scene.”
A spokesman for the police said: "Dyfed-Powys Police is at the scene of a single-vehicle road traffic collision, involving a motorcycle, on the A4069 Brynamman to Black Mountain.
"The road is currently open,but expected to close for a short time when recovery for the motorbike arrives.
"A 55-year-old man has been taken to hospital with serious, not life-threatening injuries."
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