AT least five children have been rushed to hospital in the US after they were left paralysed by a mysterious disease.

Several youngsters - all under the age of six - are being treated in Washington State after falling ill with polio-like symptoms including sudden paralysis in one or more limbs.

Health authorities and neurological experts have joined forces in an urgent bid to work out what the disease is.

All of the patients reportedly had breathing difficulties in the week prior to getting sick.

Dr Scott Lindquist, an infectious disease epidemiologist at the Washington Department of Health, said: "At this point, there isn't evidence that would point to a single source of illness among these cases.

"We're working closely with medical providers and public health agencies."

He added: "We'll continue to investigate and share information when we have it."

Health officials fear the children may have a rare condition that affects the nervous system.

The condition is called acute flaccid myelitis (AFM) which attacks the spinal cord, and can lead to arm or leg weakness and loss of muscle reflexes.

But the official cause of the children's disease is so far unclear.

AFM has been linked to several viruses and germs, including microorganisms that cause colds, sore throats and breathing infections.

The polio virus and mosquito-carried viruses such as West Nile or Zika can also cause the condition.

There have been a surge of AFM cases in the US in recent years, all of which involved young children, according to health authorities.

For the first nine months of this year, 38 people in 16 states have been confirmed to have AFM.

Specialists at the U.S. Centers for Disease Control will confirm the diagnoses. The CDC says the condition is not new but there’s been an increase in cases starting in 2014.