The Haunted Playground.

Scientists have reportedly been left baffled by a “haunted” playground swing that rocks backwards and forwards on its own.

Locals in Firmat, Argentina claim one seat swings nonstop for ten days before stopping dead, while other swings remain still.

Parents and children are convinced a ghost is to blame for the phenomenon, reports The Sun.

They reported the swing to police after it began moving four months ago,

Police officers had to admit they were stumped and called in physics professors but they too failed to find a logical explanation.

Teacher Maria de Silva Agustina said: “One child called it the Blair Witch Playground. We believe it is haunted.”

Academics have now ruled out magnetic and electrical fields, and winds - and called in ghosthunters.