An investigation is under way to establish the cause of a major fish kill in County Tyrone.
Hundreds of dead salmon have been plucked from the river
Anglers say the poisoning of at least 600 salmon in the River Strule near Omagh is an environmental disaster and it could take up to 10 years for stocks to recover.
It was initially reported that 200 adult salmon had been poisoned by pollution along a stretch of the river last Friday.
However, since then staff from the Loughs Agency staff have removed about 400 more dead fish from a part of the river near Cappagh Church.
Local anglers say it is the worst ever kill of adult salmon on the river.
An investigation into the source of the pollution is continuing, but the results from water samples are not yet known.
Jackie Hamilton of Omagh Anglers said: "We are looking at 600 or 700 fish at the moment.
"That means total disaster for this river which can take up to five or maybe 10 years to recover again. As far as fishing and fish stocks are concerned, it is a complete disaster, something I have never witnessed before in my lifetime.
"I have been here about 45 years fishing and I have never seen anything as bad as this before."
Anglers fear it could take ten years to stock the river again
There have also been other effects from the pollution, as anglers say they are coming out in a rash after contact with the dead salmon.
Some anglers who helped remove fish from the water believe the source of the poison was chemical.
Stephen Martin of Omagh Anglers said: "Shortly after I entered the water to remove dead fish I discovered a burning, itching sensation on my arms and there was a strong smell from the water.
"I helped clear out the fish and the itching continued until I managed to wash."
The Lough's Agency is pumping air into the Strule to improve oxygen levels.
A spokesman said none of its staff had suffered any ill effects but they were wearing full protective gear.