WELLINGTON, March 26 (Xinhua) -- Authorities in New Zealand's Northland region declared a state of emergency on Thursday as heavy rainfall cut off several communities and closed key highways across the upper North Island.

Nearly 2,000 homes and businesses in Northland were without power, and almost 4,000 students were affected by school closures, local authorities said.

Local councils of the country's northernmost region said the declarations, effective for seven days, would give Civil Defense access to emergency powers to protect lives and property.

A red heavy rain warning remains in place for parts of Northland, with the worst downpours expected later Thursday.

Fire and Emergency New Zealand urged people in low-lying or flood-prone areas to be ready to evacuate.