Thatcham river pollution kills hundreds of fish
Hundreds of fish have died after a "significant pollution incident" in a river tributary.
The Environment Agency said it was working to trace the source and save fish populations at Moor Ditch, a tributary of the River Kennet in Thatcham, Berkshire.
Pike, perch, brook lamprey and bullheads are affected over a 2.5km (1.5 mile) stretch of the stream.
Dog walkers and local anglers are among those advised to avoid the area.
The agency said specialist teams were "continuing all efforts to save fish populations after a significant pollution incident occurred" late on Monday.
It said that included using equipment "to aerate the watercourse with oxygen".
"All efforts are now focused on stopping the pollution and limiting further environmental damage caused by it," it added.
Members of the public have been urged to keep their animals away from the area. The agency also said local angling clubs had been informed about the incident.