The crop circle appeared in the early hours of Sunday 29 December

Video has emerged of what UFO enthusiasts claim is the moment a crop circle is formed in a California field.

Two friends shot the footage after noticing bright lights in the area south of Salinas, California on Sunday morning.

The video shows the two men leaving their car to investigate the lights and stumbling across an area where the grass has been flattened. The cameraman is heard to say: "Dude, this is a crop circle."

The morning after the video was shot, television news crews descended on the field to film the huge crop circle which was visible from the air after dawn.

The startling video was uploaded to YouTube by a user called 'Cannot Say', with the comment: "Needless to say, pretty wild, but we slipped away and it's too good not to share.

"Created this account since I don't want this tied to me. Still not sure what to make of it."

Security guards are keeping a close watch on the field and people have not been allowed to enter to take a closer look.

No one has yet claimed responsibility for creating the crop circle near Monterey.

The intricate and digital-looking pattern covers about an acre of the field.

Helicopter flies over the finished crop circle

Belfast Telegraph