Emergency officials continued their search for two pilots whose cargo plane was thought to have crashed into the sea off the Kapiti coast, about 50 kilometres (30 miles) north of Wellington, late on Friday.

A police spokesman said it was difficult to say whether Barry Crowley, 57, and Paul Miller, 50, could have survived the night in the rough seas.

South-east of Auckland, police and searchers found the body of a woman swept away on Saturday while trying to cross a swollen river in a four-wheel drive vehicle, National Radio reported.

Main road and rail routes serving the Wellington were closed by flooding and mudslides and a civil defence emergency was declared for most of the coast area north of the capital.

Civil Defence coordinator for the Kapiti coast area Rodger McCormack said the main state highway was not expected to reopen until midday at the earliest.

Auckland ferry companies cancelled sailings to outer islands Friday night in the face of gale force winds.

The unseasonally cold spring blast was expected to hit newborn lambs in the South Island where freezing rain and snow was expected.

TERRA.WIRE