Thousands of birds flew over a market, filling the evening sky in eerie scenes in Thailand.

Footage shows the flocks of swallows swarming above a commercial area, looking like dark figures with bluish grey horizon as a backdrop in Nan province on October 7 at 6 pm.

The feathered animals appeared to glide in a circular pattern while making screeching noises, causing some superstitious locals to worry.

Onlooker Nuttawoot Clangchamnan, who was outside a 7-Eleven store when the birds flew by, said: ‘There were more than a thousand. It was the first time I have seen that much bird. I believe it was a sign.

‘Some of my neighbours said it could indicate a natural disaster, while some said winter is coming.'

Barn swallows and Pacific swallows are the most common swallow species in Thailand. Barn swallows are highly migratory and travel long distances, breeding in temperate regions and then moving to warmer areas. Pacific swallows are resident species, although some local seasonal movements have been observed.