About 96,000 farmed salmon are believed to have died when a leak in a nearby tank sent 15,000 litres (4,000 gallons) of chlorine into a fjord in Arctic Norway.
Roger Pedersen, a spokesman for the salmon farming company Grieg Seafood, said the leak happened at one of its fish slaughterhouses in the town of Alta and the fish were in a waiting cage nearby at the time.
“We are connecting this to a chlorine leak,” Pedersen told Norwegian broadcaster NRK, adding the company was now handling the dead fish “in a responsible way and was investigating why the leak occurred.”
The chlorine is used to disinfect the water after the slaughtering.
On Twitter, police in northern Norway said that “significant quantities of salmon are dead” and that the leaked liquid had flowed into the Atlantic Ocean.
Police spokesman Stein Hugo Joergensen told NRK that there was no danger of any toxic chlorine gas on land. As for the cause for the leak, it was still being investigated.
Alta sits 175 kilometers (109 miles) northeast of Tromsoe, the largest city in Arctic Norway.
Grieg Seafood describes itself as one of the world's leading salmon farming companies. It has farms in Norway, Canada and off Britain's Shetland Islands. Its headquarters are in Bergen, Norway.