Clean-up after pollution incident at Four Crosses
Special measures have been put in place on a stream and river to reduce a pollution incident in Powys.
It comes after a road traffic incident in which 3,000 litres of red diesel spilled from a lorry near Llanfair Caereinion.
Mid and West Wales Fire and Rescue Service were called to the scene at 1632 BST on Friday.
They alerted environmental officials after some diesel entered the nearby watercourse. The amount is not known.
Three booms are being used on a minor tributary and the Afon Einion to stop any spillage from reaching the bigger Banwy River.
On Friday, the fire service deployed its environmental unit from Newtown to help two further crews with the clean-up operation.
Police, highways, environmental health and officials from Environment Agency Wales attended the scene.
An agency spokeswoman confirmed some red diesel - a form of diesel used for non road vehicles - had entered a tributary.
"The main job is to ensure is doesn't go into the main rivers," she said.