Hundreds of sparrows “fell out of the sky” with chilling footage showing corpses of the creatures littering the floor of a cemetery.
Video taken by stunned residents in the holiday hotspot of Bali shows the birds lying lifelessly on the ground.
Some flap their wings as they struggle to take off while many others pile up in a patch.
Local villagers said the black-coloured birds, reportedly sparrows, fell en-masse from the sky and landed in a cemetery in the regency of Gianyar on the Indonesian island on Thursday (September 9).
Authorities in Bali initially said the incident was probably caused naturally, suggesting extreme weather was to blame, even acid rain.
But a follow-up statement today said pesticides were the cause.
The birds plummeted from the sky on Thursday morning after it had been raining heavily, according to reports.
A spokesperson for Indonesia’s Natural Resources Conservation Center (BKSDA) said it was the first time such an incident has ever happened in the region.
He said: “If we’re talking about the condition and natural events, it can be said that there was a lot of acid during the rain.
“It’s possible that that caused the birds to fall.”
Meanwhile, Made Santiarka, a spokesperson for the animal health department in Gianyar Regency, also suggested the sparrows were probably killed by extreme weather.
However, a follow-up investigation on Friday (September 10) showed that BKSDA had confirmed the birds died of poisoning from pesticides typically used in the area.
Earlier this week in Wales, residents in the town of Llanrwst found a number of dead pigeons lying on the street, sparking fear of avian flu.
But Department for Environment, Food and Rural Affairs (Defra) has no alerts for wild birds in Wales for avian flu at present.
A spokesman said: “Where dead or sick wild birds are reported to the Defra helpline, we will investigate as necessary as part of our disease surveillance work.
“Results for dead wild birds that have tested positive for avian influenza are routinely published.”