This eerie footage shows countless swallows circling in the sky above building tops before dozens of them froze and dropped dead on the ground amid below zero-temperatures.

One piece of footage captured by an unnamed resident shows the flock of birds flying erratically above the buildings in Laibin, in China’s southern Guangxi Region.

Shocked observers said the swallows flew around in circles before they suddenly began dropping from the sky in the freezing temperatures.

Heart-breaking footage shows dozens of them lying dead on the road after not being able to withstand the cold.

Swallows are small to medium-sized birds known for their sleek, streamlined bodies and graceful flight. Species found in colder regions migrate during the winter when their insect prey populations collapse.

They typically have pointed wings, a forked tail, and often exhibit striking, iridescent plumage.

Swallows are highly agile in flight and many species are known for their distinctive aerial acrobatics.

These migratory birds are found on every continent except Antarctica and are often associated with nesting in colonies, and building cup-shaped nests in various locations, including cliffs, buildings, or other structures.

Species found in colder regions migrate during the winter when their insect prey populations collapse.