A lagoon in Argentina's southern Patagonia region turned bright pink due to waste from fish factories, sparking alarm among local residents and authorities.
The colouring is caused by a preservative, sodium sulfite, an anti-bacterial product used in fish factories.
Activists blamed the waste for contaminating the water table of the Chubut River and the water supply of cities in the region.
Also watch: Massive meteor lights up Norway skies; may have landed near Oslo
The lagoon turned pink last week and remained the abnormal colour on Sunday.
Residents of the region have long complained of foul smells and other environmental issues around the lagoon.