Port-au-Prince, Haiti: At least 400 people are now known to have died as Hurricane Matthew leveled huge swaths of Haiti's south, a local senator told AFP Friday.

Herve Fourcand, a senator for the Sud department which felt the full force of the impact, said he had so far recorded 400 deaths with several localities still inaccessible.

The civil protection agency for the Sud told AFP it has registered 315 deaths, with at least four towns still to report back on local fatalities.

The entire southern part of the country was inundated by torrential rains and buffeted by violent winds that lasted for hours as Matthew made landfall in Haiti on Tuesday.

The country -- the poorest in the Western Hemisphere, and one of the poorest in the world -- is particularly vulnerable to storm damage due to extensive deforestation that has left many of its hillsides bare. 

The winds and rains flooded thousands of homes and damaged schools, businesses, roads and bridges. 

More than 29,000 homes were destroyed in southern Haiti alone.

Some 80 percent of the buildings in Jeremie, the capital of the southern department of Grand'Anse, with about 30,000 inhabitants, were destroyed, according to Jean-Michel Vigreux, director of the NGO Care Haiti.

More than 21,000 people have been evacuated and 350,000 are in need of assistance, according to the UN coordinator for humanitarian affairs.

With high waters and badly damaged infrastructure, authorities fear a serious rise in the number of cholera cases.