At least 16 people have been killed and dozens wounded after a high-voltage power line hit a carnival float in the Haitian capital, setting off a stampede.

According to witnesses, Tuesday's accident happened when a musical float hit a overhead power line in downtown Port-au-Prince as thousands filled the streets for the raucous annual celebration.

Panic ensued when people jumped off the float to avoid being electrocuted setting off the stampede.

"I saw the wire falling and sparks and I started running for my life," Natacha Saint Fleur, a 22-year-old who was near the float at the time said.

Officials had earlier reported as many as 18 dead, but this was lowered to 16 by Tuesday evening.

President Michel Martelly expressed his "sincerest sympathies" to the victims in a Twitter message and his wife visited the hospitals that were treating the injured.

Hundreds of people thronged the hospital, some carrying victims and others searching for family members brought by ambulance.

The tragedy prompted the government to cancel the last day of Carnival and to declare three days of national mourning.

Source: Agencies