An investigation has been launched after hundreds of fish were found dead in a stretch of the Tolka River in Dublin.

Inland Fisheries Ireland (IFI) is investigating what it has described as a ‘significant fish kill’ near Damastown, with early indications suggesting that more than 500 fish have died.

Brown trout, eel, stickleback, lamprey and minnow were among the species discovered along a 2km stretch of the river.

The alarm was raised on Monday, prompting IFI officers to attend the scene and collect water samples as they work to determine the cause of the fish deaths.

A multi-agency response was launched, with representatives from Fingal County Council, the Environmental Protection Agency and the National Parks and Wildlife Service joining IFI’s investigation.

The fisheries body said investigators have since established a definite line of enquiry and confirmed the interagency group’s role has now been completed.

The incident comes just days after another major fish kill in Co Cavan, where more than 4,500 fish were found dead along a two-kilometre stretch of the Cavan Town River.

Inland Fisheries Ireland is also leading an investigation into that incident, although the cause has yet to be established.

IFI is urging members of the public to report any fish kills, water pollution, habitat destruction or illegal fishing through its confidential hotline on 0818 34 74 24.