Police have warned drivers to avoid a main road between Beulah and Abergwesyn.
Dyfed-Powys Police took to social media to tell motorists of the temporary road closure due to what officers simply described as an “incident”.
Using its Radnorshire Police Twitter account, the force said: “Please be aware of a temporary road closure on the A485 from Beulah to Abergwesyn due to an incident.
“If possible, please avoid the area and find an alternative route.”
Police have not described the nature of the incident or said how long the road is likely to be closed.