(CNN) -- A plane carrying three Canadians across Antarctica is unaccounted for, and inclement weather is impeding the search for the aircraft, New Zealand officials said.
The emergency locator transmitter on the Twin Otter aircraft activated at 10 p.m. Wednesday (4 a.m. ET) from within New Zealand's Antarctic rescue area, a Maritime New Zealand statement said.
The plane was flying from the South Pole to an Italian base at Terra Nova Bay, Maritime New Zealand said.
Planes and helicopters in New Zealand are ready to search, but "weather conditions are extremely challenging," said John Ashby, a search and rescue mission coordinator for Rescue Coordination Centre New Zealand. "There are winds of 90 knots at the site, and conditions are forecast to worsen with snow becoming heavier."
The plane has survival equipment and supplies for five days, Ashby said.
Canadian, U.S. and Italian authorities are also involved, the statement said.