AUCKLAND, New Zealand, Nov. 6 (UPI) -- New Zealand authorities have issued a marine hazard warning as huge icebergs drift toward international shipping lanes.

The icebergs were spotted last week by a Royal New Zealand Air Force plane on a routine fisheries patrol. The biggest iceberg is reported to be more than 1 1/2 miles long, a mile wide and about 400 feet high.

A government spokesman said the northern-most iceberg was less than 200 miles from the city of Invercargill, the closest an iceberg has been to the New Zealand mainland since 1930.