Torrential rain in northern and central parts of New Zealand has eased after four days of downpours that forced hundreds of people from their homes.

Nelson, in New Zealand’s South Island, has been the worst affected with hundreds of homes evacuated earlier in the week and some residences declared uninhabitable due to rain.

Heavy downpours have also hit the North Island, causing towns to be cut off, submerging roads and houses, and prompting evacuations.

There were about 100 new evacuations overnight across the country, The New Zealand Herald reported on Saturday.

Hundreds forced to flee

In the Tasman district neighbouring Nelson, emergency authorities said “many more” evacuations were carried out overnight, with 508 homes now evacuated in the region.

“That looks set to increase even more,” Nelson Tasman Civil Defence said on Facebook on Saturday.

The inundated area broadened due to overnight rain and now includes the Cannan-Upper Takaka area and the Richmond ranges.

Weather forecaster Metservice said on Saturday that rains in northern and central parts of New Zealand had eased, with warnings and watch alerts lifted.

A warning for heavy rain was still current for southern Fiordland in the southwest of the South Island.

“A couple of fronts are expected to affect Fiordland from this afternoon to Sunday morning, bringing a period of heavy rain in southern Fiordland, where a heavy rain watch is now in force,” Metservice said on its website.

Britain’s Prince William and his wife Kate said on Saturday they were keeping affected New Zealanders in their thoughts.

“Seeing the devastation caused by the floods in New Zealand is a reminder of the herculean effort we must all make to protect our planet,” the royal couple posted on Twitter.

-with AAP