An investigation has been launched after a major pollution incident in which 100,000 gallons of slurry was inadvertently released into a Co Tyrone river.
The incident, which happened after a slurry lagoon failed, occurred at the Owenreagh River, near Dromore on Wednesday and affected an estimated 15 miles of water.
The Loughs Agency said fish had died.
It added: "Agency staff located the source and are investigating the incident.
"Samples have been taken and despatched for analysis.
"The investigation carried on during the night, and the pollution has continued to move downstream into the Drumragh River.
"The agency has unfortunately found evidence of dead fish, and has deployed aeration equipment to re-oxygenate the water.
"The Northern Ireland Environment Agency has been advised of the incident and the investigation is ongoing."