This is the moment a woman leaped onto an ambulance bonnet and destroyed its wipers in Thailand.

The woman, named by police as Fern, 26, blocked the vehicle while it was heading to Hatyai Hospital in Songkhla province on June 9.

Fortunately, paramedics Anchalee Raknui, 35, and Passara Srirak, 25, were going slowly enough to avoid hitting her.

However, the pair were shocked when Fern suddenly hopped onto their ride, making intimidating faces at them from behind the windscreen before twisting the ambulance's wiper blades out of shape.

The apparently unhinged lady also kicked at the glass and, bizarrely, even flashed a peace sign while proceeding to destroy parts of the hospital vehicle.

Anchalee and Passara, still stunned by the encounter, reported the incident to the Hatyai Police Station, and found that Fern is actually a repeat offender.

She has reportedly been taken to a mental hospital 'dozens of times,' but would continue causing trouble whenever she is discharged. She has also allegedly been known to sleep in the backs of strangers' pickup trucks while wandering around Hatyai.

Officers have already contacted Fern's cousins to have her sectioned again. Meanwhile, the hospital operating the ambulance has filed insurance claims to repair their damaged vehicle.