The devastating effects of Hurricane Matthew on the Caribbean Island of Haiti have created the worst humanitarian disaster in the country since the 2010 earthquake, the UN has said.

The international organisation said Haiti was facing its "largest humanitarian event" in six years as authorities in the poverty-stricken nation say they have been unable to confirm how many people have been killed in the disaster.

Communications with the worst-hit areas have been cut, the Associated Press reported. A bridge in the flooded town of Petit-Goave was destroyed, preventing any road travel to the hard-hit south west.

Following the damage caused by the 145mph winds that struck Haiti, torrential rains have lashed the south of the country. The scenes were described as "catastrophic" by deputy mayor of Les Cayes Claudette Regis Delerme, the BBC reported.

She said the coastal town inhabited by 70,000 people had been flooded and winds were ripping the roofs off buildings. Delerme had been forced to flee one meeting after a gust tore off the building's roof.

The storm has claimed the lives of at least five, including a 26-year-old man who drowned trying to rescue a child who fell into a rushing river, authorities said. The child was saved.

At least 10,000 people have been taken to shelters and hospitals in the wake of the twister and tropical storm – category five when it made landfall in Haiti.

More than four million children could be exposed to hurricane damage, Unicef said, adding that there could be a general risk of the spread of waterborne disease. In the wake of Haiti's 2010 earthquake in which killed more than 100,000, cholera spread to refugee camps through infected water supplies. Six years on, thousands still live in tents and other makeshift shelters.

Weather forecasts have put Hurricane Matthew and Tropical Storm Nicole now off the north-eastern Cuban coast. The hurricane centre reported that Matthew was expected to move across the Bahamas through Thursday (6 October) and would be in close proximity to Florida's Atlantic coast by the evening.

A state of emergency has been declared in Florida and North Carolina as Hurricane Matthew makes its way towards US. As it has moved across the Caribbean the twister has slowed in speed to 135mph and has been downgraded to a category three Hurricaine.