Up to 20 people are feared dead as a power line crashed onto a Carnival float during a parade in the capital, Port-au-Prince.

The incident reportedly occurred early in the morning (17 February) sparking panic amid the thousands who had gathered in the city centre to take part in the annual celebrations.

The power line fell as a reveller on the float attempted to move it with a pole, witnesses told AP, adding that about 20 people were subsequently killed.

However in a video posted online purportedly showing the incident, the power cable seems to first hit the speaker of a float.

The crammed double decker vehicle is seen passing under the high voltage line crossing a crowded street.

A man standing at the front of the top deck, identified by local media as the singer of a group known as Barikad Crew, has his face turned and doesn't see the approaching hanging cable, which eventually touches him on the head. The man is instantly electrocuted in a flash of sparks.

He was said to be in stable condition at a local hospital, according to unconfirmed reports.

The cable is believed to have subsequently fallen onto the float, electrocuting many others.

"I saw the wire falling and sparks and I started running for my life," 22-year-old eyewitness Natacha Saint Fleur said.

Dr Joel Desire from Port-au-Prince General Hospital told AP at least 18 bodies were taken there.

Thousands of people usually attend the three-day National Carnival annual parade.