Massive spinning ice disk forms in US river

A rare natural phenomenon taking shape in the US state of Maine is mesmerising people around the world.

A giant slow-turning ice disk, measuring approximately 91m (298ft) wide, has formed in the Presumpscot River in the city of Westbrook.

The captivating natural oddity has drawn comparison to an alien spacecraft, a carousel and the Moon.

Ice disks occur at bends in rivers where faster water creates a force that chips away edges as the ice spins.

The large rotating disk has served as a raft for ducks and other birds, news reports said.